Pull away then come close?

There is a guy that I have worked with since last summer at a movie theater. We get along really well and he is a very sweet guy to me. Like for example, the reason i got a job was to save money for my first car and before I got one, he would insist that he drove me home when we had shifts together because he said it wasn't safe for me to walk home. We also had pretty deep conversations about our lifs etc...the bottom line was that I felt that he liked me, but at the same time he also ignores me. We went to the same HS and when he saw me he would just make eye contact and then walk away, even when it was just the two of us in the hallway. I went to a party recently and he was there. It was so awkward because he once again looked at me and then quickly walked away. Some days he is talkative and says "hi" and other days he ignores me totally, so what's up?