I think everyone who has tried to discipline themselves or do something difficult will realize at some point that motivation alone is practically worthless in the long run. When you feel lazy, when you feel unable, when circumstances are adverse, etc., motivation will not be what gets you up to do what you should do. Purpose will.

But I guess you have to train yourself to do things when you have no desire or motivation. It's like an exercise, each time it's a repetition. So, no motivation? No problem, it's not needed.

Cheers!