Why do some go back into previously toxic situations?

Like maybe like a week ago, I was thinking about reaching out to a ex and seeing if she wanted to be friends. But luckily I didn’t because she thinks of me as basically a toy to do whatever she pleases. Then a few weeks before that I was thinking of going back to my old job which was probably the most toxic environment I’ve endured. Like I got threats from “friends” who were obviously not friends. Then I tried to get guilted into not quitting, and some other stuff. But like at the moment it seemed I guess easier but do others do that as well? Like I don't know why I’d put myself through that again. Luckily I didn’t
Why do some go back into previously toxic situations?
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