Overall, very nice essay. I think you probably could have trimmed it down just a touch more. imho, there are multiple things going on here : reviewing a speech or revising an essay, even just in your head, is actual productive work and should be treated as such and I also tend to do this while occupied with other things like transit or exercise. There's another side too, though - relaxation or recreation. I feel like our mind like our muscles can't always be tensing and growing stronger, but that it also must take time to rest and grow stronger.