Beyond that, I think that we can miss obvious solutions even when we are working on a problem for a reasonable stretch during a single day. Say, four hours. I

Beyond that, I think that we can miss obvious solutions even when we are working on a problem for a reasonable stretch during a single day. Say, four hours. I can't count the number of times that I've been working on solving a problem for four hours or more only to discover some obvious solution (including "this problem doesn't need to be solved in the first place") when I take a break to go for a walk. As for anecdotes and swaying decision makers, anyone who keeps a personal journal of what happens during a day and how much they've been sleeping will quickly correlate bad days with sleepless nights before. "Unlucky" events are more common on less sleep.