replaying scenarios in your head usually gets you nowhere

I think it can be a way of processing an outcome and learning from it. Of course I think we all do this to a degree. The trouble happens when we get stuck, instead of learning from it.

Sometimes it's all you got

I disagree. We can all learn from History - our own included.

You're right, of course. "What if?" is a surefire way to stagnate your life.

the Buddhists taught that.

True. As long a you understand them, you can move on

True, yet most of us keep on doing it anyway.

It doesn't but all it does it bring loads of sorrow.

Agreed