Not only do I believe the myth of Sora needing to mature is false, I think Sora is already easily the most mature out of the main cast. Yeah, he smiles and has a good time, but if you look at how he deals with problems and situations before him, he handles things in a far more mature matter than others.
First, let's talk about that old trigger of misdirection and hurt feelings: communication. The ability to exchange thoughts and ideas and making sure that everyone is on the same page. Especially important when tensions are high, so that no one gets angry for the wrong reason, and helps everyone keep as level a head as possible. Failure to communicate is one of the leading causes of avoidable drama in the series. Xion puts a strain on her friendship with Axel and Roxas by constantly running off without explaining why. In turn, Axel likes keeping all of his cards close to his chest to the point of folly, where Roxas feels really quite betrayed by his friend. The entire situation with the BBS trio could have been solved if all three characters actually talked about what it is that they've been doing, rather than listening to one sentence and then jumping to whatever conclusion they preferred. What matters in all of this is that not communicating during a problem or crisis is not the mature thing to do. The character's refusal to communicate is usually caused by selfish or petulant impulses, or just a refusal to listen to any opinion other than their own and examine the situation to a greater degree.
Flipping over to Sora, who actually is willing to talk with the people he's having problems with and try and reach a common understanding. Throughout KH1, he keeps trying to reach out to Riku, in spite of the latter being a complete jerk; the same as in KH2, where, if not for Sora's willingness to communicate, Riku would still be brooding in a corner of the Dark Realm somewhere. In spite of his problems with Namine, his willingness to listen to her side of the story and understand the issue fully produces dividends later on. What matters is noticing how Sora keeps trying to understand all sides of the situation, and tries to keep everyone involved in the conflict on the same page. If he just said, "Shut up, Riku, you suck!" there would be a lot more problems later on (that door ain't gonna close itself). By trying to keep communications up between people, things are left open for negotiation later on, with far less hurt feelings and a greater understanding of positions from the involved parties. Problems are avoided as a result of Sora's ability to talk things out and reach understandings.
Which segues nicely into part 2: how to deal with a spat between friends. It's a fact of nature people are going to get angry, and not everyone is going to get along all the time. Even Sora: when we crash in Deep Jungle, he and Donald are miffed with one another. Yet, they are able to continue working alongside one another, and eventually let their tempers cool down to the point where they apologize to one another. What matters here is the acknowledgement of Sora that you can't just storm off and pout and go solo just because you had an argument. Sometimes, you have to work with someone you might not like, but you're going to work with them because you know that it's going to get more done than if you both keep throwing hissy fits. Not to mention that, at the end of it, you might just find yourself cooled off to the point where you can do some introspection and not only find that you can forgive the other, but you can admit that you yourself should be apologizing. This is probably one of the most mature things you can do when encountering a conflict: not letting it impede the work that needs to be done, the ability to introspect, and being able to wrap it up at the end without holding a grudge.
It's a pity that few people in the series seems capable of doing this. Riku is miffed because he thinks Sora is running around having adventures without him/ is now exerting alpha male tendencies which doesn't sit well with Riku's ego, and decides to run off and join the evil circus, gradually becoming more and more embittered towards his friend, to the point where, ultimately, he has no problem with either summoning a Heartless mimic to kill Sora, or swiping his keyblade and telling him he sucks. Again, failure to communicate, but also the fact that Riku just can't reconcile with his problems, and prefers to resort to the equivalent of sitting at the back of the class and throwing balls of paper at Sora's head. Each of the leads in BBS have this problem too: storming off and pouting, rather than trying to keep each other on the same page, seems to be par for the course. The point is that everyone seems to be more involved with trying to justify themselves to satiate their own egos rather than actually looking at the problem and wondering whether or not they've done anything to solve it.
Also on the note of overcoming conflict, we need to talk about Riku in KH2. He spends the game running about in the shadows because he's understandably ashamed of his actions, and wants to make amends. Yet he can't bring himself to talking to either Sora or Kairi, because he feels that its better to leave them alone. As much this plot point works for both the story and Riku's character arc, I think its worth pointing out that it's not really the most mature way to handle things. Mainly because, by not talking to Sora or Kairi directly, he's not actually facing his problems. In fact, he spends most of the game trying to avoid the thing which he needs to do the most: actually apologizing directly to the people that he's hurt the most. He's finding an out through self pity, when the mature thing to do would be to admit he was wrong to his friends. And, again, communication and Sora's ability to not hold a grudge are what saves the day: once Riku finally has to talk with Sora and Kairi and discuss what happened, they are able to get over the problem, move on with their lives, become friends again, and once more work together to overcome a greater problem. This only happens because Sora is mature enough to know how to handle a conflict between friends, and is able to use that maturity to guide his old buddy into calmer waters.
I think what's important to note is that "mature" does not mean holding up a wall, wearing all black, and brooding. It's about your actions and what you do in relationship to others. People think Sora is immature just because he doesn't spend his time being sullen, yet I think its for exactly that reason that Sora is, in fact, mature. He is able to see a problem in a wide scale, take into account the different people involved, and find an answer that hopefully makes the best of things for the most amount of people.
Not only do I believe the myth of Sora needing to mature is false, I think Sora is already easily the most mature out of the main cast. Yeah, he smiles and has a good time, but if you look at how he deals with problems and situations before him, he handles things in a far more mature matter than others.
First, let's talk about that old trigger of misdirection and hurt feelings: communication. The ability to exchange thoughts and ideas and making sure that everyone is on the same page. Especially important when tensions are high, so that no one gets angry for the wrong reason, and helps everyone keep as level a head as possible. Failure to communicate is one of the leading causes of avoidable drama in the series. Xion puts a strain on her friendship with Axel and Roxas by constantly running off without explaining why. In turn, Axel likes keeping all of his cards close to his chest to the point of folly, where Roxas feels really quite betrayed by his friend. The entire situation with the BBS trio could have been solved if all three characters actually talked about what it is that they've been doing, rather than listening to one sentence and then jumping to whatever conclusion they preferred. What matters in all of this is that not communicating during a problem or crisis is not the mature thing to do. The character's refusal to communicate is usually caused by selfish or petulant impulses, or just a refusal to listen to any opinion other than their own and examine the situation to a greater degree.
Flipping over to Sora, who actually is willing to talk with the people he's having problems with and try and reach a common understanding. Throughout KH1, he keeps trying to reach out to Riku, in spite of the latter being a complete jerk; the same as in KH2, where, if not for Sora's willingness to communicate, Riku would still be brooding in a corner of the Dark Realm somewhere. In spite of his problems with Namine, his willingness to listen to her side of the story and understand the issue fully produces dividends later on. What matters is noticing how Sora keeps trying to understand all sides of the situation, and tries to keep everyone involved in the conflict on the same page. If he just said, "Shut up, Riku, you suck!" there would be a lot more problems later on (that door ain't gonna close itself). By trying to keep communications up between people, things are left open for negotiation later on, with far less hurt feelings and a greater understanding of positions from the involved parties. Problems are avoided as a result of Sora's ability to talk things out and reach understandings.
Which segues nicely into part 2: how to deal with a spat between friends. It's a fact of nature people are going to get angry, and not everyone is going to get along all the time. Even Sora: when we crash in Deep Jungle, he and Donald are miffed with one another. Yet, they are able to continue working alongside one another, and eventually let their tempers cool down to the point where they apologize to one another. What matters here is the acknowledgement of Sora that you can't just storm off and pout and go solo just because you had an argument. Sometimes, you have to work with someone you might not like, but you're going to work with them because you know that it's going to get more done than if you both keep throwing hissy fits. Not to mention that, at the end of it, you might just find yourself cooled off to the point where you can do some introspection and not only find that you can forgive the other, but you can admit that you yourself should be apologizing. This is probably one of the most mature things you can do when encountering a conflict: not letting it impede the work that needs to be done, the ability to introspect, and being able to wrap it up at the end without holding a grudge.
It's a pity that few people in the series seems capable of doing this. Riku is miffed because he thinks Sora is running around having adventures without him/ is now exerting alpha male tendencies which doesn't sit well with Riku's ego, and decides to run off and join the evil circus, gradually becoming more and more embittered towards his friend, to the point where, ultimately, he has no problem with either summoning a Heartless mimic to kill Sora, or swiping his keyblade and telling him he sucks. Again, failure to communicate, but also the fact that Riku just can't reconcile with his problems, and prefers to resort to the equivalent of sitting at the back of the class and throwing balls of paper at Sora's head. Each of the leads in BBS have this problem too: storming off and pouting, rather than trying to keep each other on the same page, seems to be par for the course. The point is that everyone seems to be more involved with trying to justify themselves to satiate their own egos rather than actually looking at the problem and wondering whether or not they've done anything to solve it.
Also on the note of overcoming conflict, we need to talk about Riku in KH2. He spends the game running about in the shadows because he's understandably ashamed of his actions, and wants to make amends. Yet he can't bring himself to talking to either Sora or Kairi, because he feels that its better to leave them alone. As much this plot point works for both the story and Riku's character arc, I think its worth pointing out that it's not really the most mature way to handle things. Mainly because, by not talking to Sora or Kairi directly, he's not actually facing his problems. In fact, he spends most of the game trying to avoid the thing which he needs to do the most: actually apologizing directly to the people that he's hurt the most. He's finding an out through self pity, when the mature thing to do would be to admit he was wrong to his friends. And, again, communication and Sora's ability to not hold a grudge are what saves the day: once Riku finally has to talk with Sora and Kairi and discuss what happened, they are able to get over the problem, move on with their lives, become friends again, and once more work together to overcome a greater problem. This only happens because Sora is mature enough to know how to handle a conflict between friends, and is able to use that maturity to guide his old buddy into calmer waters.
I think what's important to note is that "mature" does not mean holding up a wall, wearing all black, and brooding. It's about your actions and what you do in relationship to others. People think Sora is immature just because he doesn't spend his time being sullen, yet I think its for exactly that reason that Sora is, in fact, mature. He is able to see a problem in a wide scale, take into account the different people involved, and find an answer that hopefully makes the best of things for the most amount of people.