I know what you mean. Many years ago, there was a girl in high school I had a bit of a thing for. We seemed to have a lot in common, but for some reason we just never clicked.
Some time after that, it turns out we lived in the same city. She sent me a message and we got together. We worked in the same field. We were interested in the same things. We even had the same favorite book! We went out a couple times, but there was just absolutely nothing there.
Ah, well.