Re: I Don't Know Whats Happened?
Whenever you do something that you're not so sure about (like fool around), you get 'Buyer's remorse' (or maybe in this case, 'Fooler's remorse'?). That's the reaction when the initial enthuasiasm wears off (usually after you do whatever it is you wanted to do), and you're left with the nagging question if it was worth it or okay to do in the first place.
Two things could account for your bud's reaction. First is that he's decided that it wasn't worth it, and that the feelings he has towards the stuff you did has rubbed off on you. The second explanation is that his reaction to you currently has absolutely nothing at all to do with you, but it's just one of those things, he's 'moved on'. That too happens, people grow apart.
You can usually tell the diff when you talk with him, either by directly asking him if everything's ok, that you notice some distance, and wasn't sure why, or when you just talk with him in general or just around him if he seems 'weird', as in avoiding eye contact, if he's unusually sarcastic, etc., other indirect ways of communicating bad feelings towards you.