Why would a guy go out of his way to talk to me if we barely know each other?

So I’m a freshman in college and I focused on school in highschool so I didn’t date. Basically I have intuition but I don’t know much about guys. So This guy I think is handsome and sweet has been a assistant for my teacher for years before I came. He’s quiet but still very nice to everyone. we never had a conversation one on one. When we first met I caught him staring at me multiple times but he stopped. Yesterday I went to my teachers office and he was there and he told me the teacher wasn’t available. I left to go to the study rooms and I and I was surprised to see he had followed me. He said “tell me about (this class)” he’s the assistant I’m sure he knew everything but then he looked overmyhomeowork and started explaining it showing how smart he was and kinda showing off . Then he left. What does this mean