He isn't wasting his time because at the end of all of this he is going to learn something about himself. Not sure what that is yet, maybe one of these...
1. I shouldn't have treated that girl so terribly. I'll treat the next girl better.
2. That girl was crazy pants. Better make a better evaluation the next time before I sleep with someone.
3. Man, that was the one that got away. I could have really loved her if I would have taken the relationship seriously.
4. Girls really like it when I do that thing with my tongue.