I've only wanted a romantic relationship with one person - a girl I knew back in school. We were in the same class for about 3.5 years, and most of my personality and taste today comes from wanting to impress her. I started listening to music, tried to learn musical instruments, picked up a bit of dancing, read the Twilight and Percy Jackson books, and became interested in media mostly to have something in common. Ironically, we became closer friends when I stopped trying to do this consciously, but by then I'd already developed a taste for this. We kept in touch for a long time, till we went to college in different parts of the globe.
Even now, I'd give anything to have her around. Even having sex despite being asexual.
EDIT: I forgot to mention, I never told her how I felt about her. When she ended up getting a boyfriend, I jokingly told her that she had said back in 7th grade that she'd never get into a relationship, but a bit of me died there.