I think we all have a tendancy to 'ruminate' it's just some of us more than others. I would suggest those mentally ill do more often.

Yes, thing tend to weigh me down at night when I having nothing but time to myself and go back over my day but, it also happens when I stand in the shower. Yes, I'm not kidding. It is in the shower that I most feel battered down about all the negativity in my life.