Earlier quoted context omitted.
Motivation is fleeting but routine persists. When there is something that you want to do regularly (exercise, doing the final boring part of some sideproject, cleaning the house...) you remove willpower from the equation and set a day and a time. For example, everyday from 18 to 19 I work on my sideprojects, or saturdays from 16 to 18 is house cleaning time. There is no question if I want to do it, it is set at that…
As someone that is unable to keep any sort of routine, I have objections here. :D Without some sort of obligating circumstance, it is incredibly easy to forego what would have otherwise been today's routine.
I've had routines at times in my life for months. And they disappear in a matter of days when I get stressed or my schedule changes or whatever.