I doubt so.
I've seen 14 year olds who are MUCH more mature than you.
You can't be 15.
Well, I'm 12, so there goes your philosophy.
Anyways, I don't need to give you an example of a clan rivalry.
They don't end in 'flamewars and trolling' either. They are purely for fun. You go to a Clan Wars server, have your clan fight another Clan in a deathmatch.
It's not like they actually dislike each other.