Falling for a stranger

It's totally absurd and unheard of, yet it happens. There's that moment of attraction and you feel something stir inside you. When he looked at me, i don't know, i feel flattered. Instead of just looking away when he stared at me, I stared back. And it lasted like hours.
I met him at a program or motivational talk. I noticed him since the first time he step through that door. I didn't think I'd be lucky enough to be paired up with him for the team work part. I was separated from my friend who was sitting at the same table as him. When the speaker told us to team up with the members in the table, I was the only extra one. My friend took that opportunity to raise up her hand and said she doesn't have a team mate too, hoping we would be paired up. But alas, the speaker decided to choose him to pair with me. He was really kind and caring as he guided my through the teamwork task. After the task ended, we went back to our respective seats but all the while during the almost 8 hours talk, we keep making eye contact. I noticed him staring first, I wasn't sure if it's cuz I was in his line of view or cuz the door is next to me. The speaker kept walking over to his place so I took that at an excuse to look at him. We even got grouped up again to person a stupid chicken dance as a punishment.
We never knew each other's name or contact number. I was too chickened out to ask and I never thought we'd see him again. I'm sure he's a senior from another faculty. After the program ended we really didn't see each other for a long time. Until one day while I was in town with my friends, I met him again. At first I thought, his face was really familiar, then it hit me. I kinda froze, in the middle of the road (good thing there's no car). I waved and he waved back (tho I didn't see it) I was too stunned. Anyway, cuz we're in the middle of the road, I had to move. Instead of following him to ask for his name, I didn't. I regretted it again. After that encounter I couldn't get him off my mind. My friend said it's infatuation. I don't know. I don't understand why I could be infatuated with someone who I have literally no knowledge about. 
I saw him again this semester, twice, and always at a very inappropriate place and time (Like when I was rushing to class and he's making his way through a crowd of people) Every time, I couldn't muster the courage to go up to him and talk. I feel like a teenage girl again which makes me really ridiculous and ashamed of myself. After these two times, I really never saw him again. And I regretted it AGAIN. He keeps popping up into my mind recently and I don't know why. This morning I went out for a run in hope to get him outta my mind but it doesn't seems to be working isn't it?
I've been annoying my friend about this, telling her the same story over and over again. Asking her why I'm feeling and thinking this way. She always came up with the same answer and told me to pluck up my courage next time I see him. Then I thought yeah, I really should.
So the next time I see him I will walk up and talk to him. The problem is, I'm afraid I'll never see him again. I don't know, I've been given chances and I let it go. I'm praying for another chance and hoping that I'll be granted.