My brother developed like Sasuke Uchiha, how does that work?

First of all as a warning: this will be a long text

I have a very good friend who I've known since I was a child, he came over every weekend. I know his family and he thinks I meet his mother every week via. My mother. Likewise, his uncles are also roughly my uncles. The same applies to grandpa, although I honestly say that I see him as my grandpa and love him just as much. We're kind of a family.

My brother was a pretty open person as a kid who tended to be stubborn - and still is. As children we did everything together: Played PS3, going out into the garden, shopping, New Year's Eve, Easter, Christmas etc. As we got older, however, he grew more and more apart from all of us (including his mother). He didn't speak to me extremely openly anymore, in Minecraft he changed his name to something like Dark Oder (we were 13 or 14 then). He also stopped letting me take part in the YouTube videos he was watching. I wouldn't care about anything, I didn't care, after all, he's my brother- I thought. Up to the point where he stopped telling me and his mother about his problems or hiding (alleged) problems. So I wanted to know why that could be. He has looked at many Minecraft Youtubers, aged 14, who have always played with dark textures & names, as well as expressed "mysterious". I also watched these Youtubers (not that much) for a long time, so it couldn't be so blatant. But I noticed that he started (when he was 15) to watch Naruto exaggeratedly. Well, the whole thing has been dragging on for 3 years now, because I didn't watch Naruto myself, I couldn't know. He has really developed into a complete loner and is stubborn like a bull, is always right, already knows every experience and can't be taught anything. At least that's what my cousin and a few other relatives say, but unfortunately I have to agree.

Well I'm interested in what it was that made him develop so much when we have such a wonderful family. That's why I just started watching Naruto. Wonderful series. I'm currently at Naruto Classic and it knocked me over how my brother resembles the protagonist Sasuke Uchiha. He is just like Sasuke - always "cool" & mysterious or does not talk to others because they have nothing to do with his life. This is really too incredible. We'll both be 18 this year and if I'm honest I want my brother back. My mother and his mother always said that this is only a phase and it will be over at some point, but now I wonder when? We already live so incredibly far apart that we maybe see each other once a month while he lives just 10km away, and his & my mother can drive us at any time

People change. You are no longer the same as you were at 13 and you will look back on today with a smile at 33.

Your brother has taken a different turn and if he doesn't have a medical background you will have to accept him that way.

Time can't be turned back.

I think your colleague is old enough and doesn't want to be like sasuke.

I think that's a trait that your colleague develops. I'm assuming that it is "just" a phase, but I don't know when it will end either. It could be that it will loosen up, but you can't say how much.

Some people are just more closed than others. If this has been going on for 3 years, I assume that it will take a while before it becomes the same again.

If your colleague has not really experienced something that made him feel so closed, I assume that he got too involved in the attitude that he saw in others.

But even if your colleague stays like this, there's no reason to say goodbye.

Thank you for the answer! Fortunately there was no extremely dramatic event that somehow pushes someone into such a situation.

Already clear, but unfortunately the problem is that he always treats us and his mother as strangers.

The thing is: you are only writing about your subjective impressions. Someone else might have. A completely different view of your brother. So that's just poking around in the fog.