Best way to look at it! It is their loss and your gain! I knew this girl growing up and I had a crush on her, but she choose someone else.
Many years later, I met her in a shopping mall with three kids and what a mess! The beauty is all gone, completely overweight. Looked like she switched bodies with an alien being. You see what I was saved from?
Do not even think about it and move on, time would tell.