Some People choose poorly....multiple times.
Yep. Marry, divorce, seek same type on the rebound, lather, rinse, repeat.
They don't take time after a failure to sort out how they contributed, if they contributed, and to figure out what went wrong. If they can't own at least making a poor choice, and figuring out what was wrong about it enough to avoid doing so again, or what they may have done to make things not work, the next time is unlikely to be a success, too.
I'll just say this, if you can't be best friends and not just lovers, your chances diminish markedly.