Great anecdote. I try to apply this philosophy to endurance training like running (just get to the next mile marker), swimming (just do the next lap) or biking (just do another minute) but it's really hard. I'm awed by the special forces guys (or the author of the post) who apply that kind of thinking to long periods of time.

It does seem to me though that for creative thinking or solving really tough engineering problems that rest and laziness can actually be productive. So I don't know how to reconcile that with "training my grit muscle". It seems both are important.