I do this all the time. With recent grants, sometimes old grants. With papers. With talks that I think went well. I don't think it's time wasted. It's about learning what good looks like, and reminding yourself that sometimes you can be good. 2 of the most important things for an academic.
Tim Behrens
Does anyone else waste time at work occasionally re-reading bits of a submitted (but not yet reviewed) grant? I can't seem to help myself, despite knowing it is completely pointless