I've had trouble working on one of my research-related subproblems for more than an hour or two a day. I started visualizing myself explaining to a peasant farmer ancestor that, really, working for more than an hour a day on this subproblem was just too hard. That's been motivating me to put in closer to 4 hours (with a commensurate increase in results), but I don't know how much staying power that visualization will have. Probably enough to finish our this subproblem (I only have ~15 hours more work to do), but imaginary shame only goes so far.