Why is it so difficult for some people to NOT play with peoples feelings

I've liked this one boy for ~a year now. He gives me so many mixed signals I am going insane. One day he'll be waiting at my desk, asleep, when I come back from class and the next he treats me like everyone else, and then the next he'll be sitting right next to me while we talk with his elbow resting on my knee and making immense eye contact. I can't take it. Why can't he just say if he likes me or not. Are we just friends or nothing. I hate it I hate it I hate it.