confsued.. having loads of guy problems!!!

Hi, Im *Aj... some thing happend at school and i dont understand it, im am very confused so please help me... there is thsi boy in the nineth grade and im currently in eighth grade. well today he came to sit by me during break, we had a nice chat, when break was over we went our seperate way... but i saw him again during Mathematics and he didnt even acknowledge the fact that i was there, it was like he never met me at all...and some days he acts all inlove with me and the next its like he doesnt know me at all... what does it mean?