Yeah I think parents have the tendency to bring up the past in general a lot and it doesn't even have to be bad stuff either. I've never thought of not having enough to occupy themselves in the present but it does make sense. I'll admit I'm most likely to think about past events when I'm not occupied in the present as well but don't obsess over it like parents do. I agree when parents and even anyone else keeps bringing up past events in such a way as if it just happened yesterday then I start mentally thinking "let it go" and a couple times I did say that it's in the past and I've let it go.