Motivation is typically short lived, building discipline allows you to not be subject to its fickle nature.
(some people call it habit, I call it discipline)
Agreed. Learning to divorce tasks from motivation is an important skill to learn that might be worth looking into more, and habits/routines are great to build, but just telling people to do things anyway isn't really helpful.
"How do I do X when I don't have Y?"
"You do X even though you don't have Y."
"Okay, but how? My problem is that if I don't have Y, I don't do X."
"Well just do X without Y, and then you won't have that problem."
"Right but..."
"You know the problem you have? Stop having it. Then you won't have it."