When I was 12 or so a girl in church had a crush on me. I was oblivious to it until one day when she sneaked up behind me and threw her arms around my waist, and scared the hell out of me. After that I avoided her.
Last year I met a girl at a poetry festival. I admit I flirted with her a little bit, and we exchanged phone numbers, but ugh! For months she kept sending me text messages, even though I tried to let her know as kindly as possible that I just wasn’t interested. Eventually the text messages stopped.
Freshman year I met a girl who I had a crush on off and on for (well, I’m a senior now, and I might still have a crush on her, so) maybe four years. In between we both had relationships with other people, but we never got together. She moved away last year. In hindsight it’s easier to see that she had a crush on me, off and on, for that entire time as well. At the time when it mattered I didn’t realize it.
edit: @Bri: Freshman year I almost passed her a “check yes or no” note. We were in the same english class, and our teacher was talking about a time when she received one of those when she was in elementary school. (No one in our class had ever heard of such a thing.) I got as far as writing the note, (and looking back, I know which box she would have checked) but I didn’t have the balls to pass it to her. I really regret that. It’s like that scene in Steppenwolf, where Harry goes through the “ALL GIRLS ARE YOURS” door, and says that that one moment where he passed by a girl he liked rather than saying hello was one of his greatest regrets. Unfortunately I don’t have a magic door to go through.