I suspect that part of that is a guilty conscience.
There seems to be something in us that needs to confess our wrong.
I have an acquaintance who is in a volatile marriage, (and she's as much to blame as he is, if not more)and after they have a fight, she seems almost compelled to mention it.
I had another acquaintance (who I've cut ties with) who would also tell me stuff that I couldn't believe she was doing.
I don't know if they were looking for approval or validation or whatever, but it seems to be something in human nature to do that.
They know they should feel something about what they are doing but they are not sure what. So they tell everybody to figure out how they should feel about it.
I thought being a manager was bad but I never realized how many people were eager to pour out the details of their lives until I started working in a store.
At least it used to be just the people who worked for me. Now it is total strangers. And people that are totally strange.