Most people aren't in relationships that are worth repairing anyway, it seems.

Sure, but most things can be worked through. Breakups, divorces, infidelity, you name it.

But thank you anyway, I think I understand how you mean.

Why would it not be up to me to undo my wrong move, if it was a wrong move?

Because I'm not the most internally/mentally stable and consistent individual and there are certain factors that affect my reasoning and behavior. I guess.

For example, my attachment style is quite clearly avoidant. That means that I deeply crave intimacy, but at the same time distance myself from people when they get too close, like in romantic relationships. I find it very hard to commit, often fixate on the negatives (no matter how miniscule) and so on, if that makes sense.

Basically, I can't fully rely on my "gut feelings" about people because some of my defense mechanisms masquerade as gut feelings.