My first big crush was my freshman year in college. He worked downstairs in the library and would monitor the listening rooms. I went there often to listen to recordings of music in part because I was a music major, but also to cross paths. It was never reciprocated, but it's just as well. I don't think my imagination and reality were especially well aligned at that point. He also liked bubbly girls. Most of my "dating" years consisted of crushes in which I thought I was communicating interest, but whether or not I succeeded, there was not a response. I think I had a bad combination of being dense when someone showed interest, and overly subtle in expressing interest.
When older, I just took greater risks, and lucked out somehow.