Great article, although I wonder about the assertion that willpower is a solo thing. Surely social pressures act as motivating forces on our will to do things - for instance if we tell a few friends that we'd going to run a marathon then we'll be more likely to train for it. Or even better, if we agree to meet a friend at the gym at 7 then we're much more likely to get ourselves to the gym than if we just write "gym at 7" in a to do list.

But perhaps this only applies to initial motivators and isn't enough for focus (sustained motivation to concentrate on a task)