That's just how we are

I guess this is just how we 15-year-olds are: We try to act like we're all mature, yet in the end we just act like 5-year-olds. And I'm not even trying to hurt anybody or whatever, I just thought about it just now. I asked how someone's 15 years old brother acted, and apparently he acted like a 5 years old. Well, I'm 15 too and I usually act like a 5 years old too, and I know more people from around my age who act like that, so... Maybe that's just how 15-year-olds are?
Anyway, guess I'm going to be alone in the next days again. Well, this really sucks, but it's my own fault anyway. Wish me good luck ignoring whatsapp. I usually want to check it a million times because of the groupchats I'm in, sometimes they really can't stop talking so yeah.