There are things we do that have pretty clear implications on the time scale of a year or ten years. I think it's kind of not hard to imagine that we're bad now at predicting what the world willbe like a hundred years in the future. A big chunk of your work comprises of, among others, stretches of time dedicated to just thinking. Do you ever get said frustrated or otherwise uneasy when you don't seem to progress in any obvious way? During such sessions, y for a longer period of time, have you ever felt that you've wasted the time? So how do you deal with that? If not, why do you thnk that's the case?