Many wax lyrical about motivation and willpower.
Motivation and willpower are completely overrated.
Like any big effort is 99% Perspiration, 1% inspiration, I would say it is also 99% habit, 1% motivation and/or willpower.
Motivation and Willpower are the skinny pair of sass and bide jeans that barely cover your arsecrack, Habit is a comfy pair of tracky pants that you happily change into after a day of hauling up your tight jeans.
M and W are the test you cram for and worry about having failed, H is the movie you can quote verbatim.
M and W are the annual rego (or insert other big cost here) bills which you scrimp and save for, H is the weekly $10 from your direct debit for your gym membership.
M and W are the hare, H is the tortoise.
M and W are like a surf beach and H is like a calm little bay.
Being overwhelmingly creatures of habit, it is far easier to default to this than to rely on motivation and willpower.
This is what I have learned. For good and for bad.