Do you regret dating any of your exes?

Yes I regret dating most of them.
Why? It was a waste of my time and money.
I did learn not to trust others, that relationships are an absolute waste of time, and I did learn that I hate sex.

Worst dating experience? I was once dating this guy who lived two hours away from me. One day I get a phone call at 4 in the afternoon, saying that he had hitchhiked to town and needed me to go pick him up. I lived 20min drive from town and didn't have a car. He ended up staying with me for a week until I got paid so I could pay for him to go home again. I had to pay for him the whole week he was with me, as well as get my studies done.
It's not so much a dating story, but this happened multiple times with different guys. One night stands, they don't leave, txt me constantly, get emotional when I don't respond, then give me presents. This is after knowing them a day. The ex in the previous story had the same behaviour.