This is inspired by a post on the relationship advice sub. I have heard this term as well, "she was the one who got away". If a guy feels like this about a woman, he is definitely not over her. He will harbour feelings for her always. And if she is around, he will always be waiting to hook up with her as and when she is available.

Generally, people put their feelings to rest by understanding why it didn't work out. If timing is the only reason it didn't, AND she is still around, there are plenty of chances for the timing to be right in a marriage. In a state like this, you are just the woman he is filling his time with, the real woman is the one who got away.