is this weird?? and why is he acting like this?

[xxHeartlessxx]

so theres this guy whos in two of my classes, and he didnt know me, until i started talking to him randomly about the class, and he was really nice and helped me with some problems, and then when i was about to go, i told him id see him in the other class we had together. and hes like 'oh your in that class too' and i was like yea i think ive seen you around...so the next class he ignored me, even though he walked past me, and i tried to make eye contact, and we sit in the same row, but about like 5 seats away. and then the next class we had together i left my hair out and actually put an effort into how i looked, and i thought he would ignore me so i tried to look at the floor to avoid his gaze, and he tries to make eye contact with me, and when i was walking back to my seat i saw him looking at me, and he says hey whats up... i want to get to know him, but i dont know what to talk about since he ignored me i felt kind of rejected.
soo my question is, isnt it weird that hes acting like this? and why?