Why was a boy being mean to me then started being nice?

i'm a girl who moved to a new school and met a friend who totally gets me. But she has a friend whom is a boy started being rude. Then, when it's almost the end of school, he starts talking to me in a nice manner.Why?!

You'll drive yourself crazy trying to understand why people do the things they do.

A better approach may be to decide how you feel about the treatment, then act based on that. So, if you're ok with how he treated you in the past and how he treated you more recently, then react based on that. If you don't, then react based on not liking it.

Never mind the why for now.