You become what you repeatedly do

"Don't spare yourself" is the key motivating factor in some Zen monasteries. By working hard and not wasting a moment they are training their subconscious to become infected with enthusiasm. If they keep at this until it becomes a habit, soon the rest of their being obeys.

Armies do this too. In boot camps new recruits wake up at the crack of dawn, make the bed neatly in 20 seconds, take a shower in exactly 2 minutes and so on. Initially, they only act like they are self disciplined to avoid punishment, but soon acting sharp and smart becomes a life long habit even without the drill sergeant.