Replying to One of my best friends isn't my friend anymore..

So today i just saw one of my good friends i haven't seen all summer, he goes to my school but i hadn't seen him around,we use to be good friend from 7th and 8th grade we hung out all the time, in 9th grade we chilled alot, now he just became a total dick to me, talking shit to me all the time and i was like wtf did i ever do to you, now he isn't talking to me and just shits on me, ever happens to u guys?