Have you ever been happy a relationship didn't work out?

About 6 or 7 months ago I asked this girl out. She was pretty and at the time I thought she was smart. We went out on one date and everything turned out fantastic. So naturally I wanted to go out again but she turned me down.

It turns out I got lucky things didn't go any further. She was a few months pregnant during our date, her boyfriend ended up beating a guy senseless just for talking to her and once she had the baby there was some other guy who claimed to be the father.

So I ended up dodging a bullet. My question to you all is has there ever been a time that you tried to date(or did date) someone and later you were glad that things didn't work out?