I believe the main reason why most people make the same relationship mistakes over and over again is because they never ever really took responsibility for the choices (they) made with their mate selection.
Whenever things go badly they blame their mates instead of examining why (they) chose their mate to begin with. You can only learn from (your) mistakes. If you really believe it's always the other person's fault then you believe you are "powerless".
These same people tend to believe "You can't help who you fall in love with." In reality each of us chooses our own friends, lovers, and spouse. We get to (choose) who we go out with, spend time with, have sex with and so on. You can't say "yes" a thousand times and then turn around and claim "it just happened".
If you go to the grocery store to purchase an apple but buy an onion instead whose fault is that? Do you curse the onion for not being an apple? No! You learn to become a better shopper!
Too often people get with others whom they hope they can "change" overtime. When it does not happen it leads to frustration on their part and resentment on the part of their mates. They'd be better off finding someone who (already is) the kind of person they want to be with.
Until someone takes responsibility for their mate selection process they aren't likely to see that it is them who has been making mistakes.