I just wonder something about guy?

I met him for the first time & have a crush with him 10 years ago. Hell yes, I do some weird things to attract him.but he was a real mr. shy guy. I try hard to make it. The last of his day in our school, he stared at me (the things he never dare to do before) but still he can't even facing my eyes when we are face to face and he is shaking. Then, he move but I still can see him from afar somewhere in our neighborhood. Still the same; shy, quite and only his eyes can hold on with staring at me. Then I lost him. Last two years ago I found him again. He seems to avoid me when he knew who I am. I just want to befriend with him but he does'nt give me the chance and he has a girlfriend already. I am so frustrated because all those years were wasted to find and wait for him. I met other guys but still can't forget him until now. I just want to say I love but it only for yesterday so I don't have to feel regret anymore. I try to forget my past but since I can't forget him I think it is better for me to tell him what I feel for a decade ago. I just want to let the feeling gone by telling him. I really hope I can start a new life and new with other guy at least. Why is it so hard to understand this guy? When he knows we are from the same school, he change his mind and mood in out of blue and avoid me. I really want to know what was in his mind. Is it so bad entering the same school with me or did something bad happen in him at the moment before?