Motivation is a weather event. It arrives, it feels enormous, and it is genuinely useful for starting things that would otherwise never begin, but it was never built to sustain anything. Discipline is what operates in the cold, when the feeling is gone and the work is exactly as unglamorous as it always was. Most results are produced entirely in that second period.

Assume the enthusiasm will leave and design for its absence. Decide now what the minimum version looks like on a bad day, and make it small enough that it survives a cold room. Then keep that version, especially when nothing about it feels meaningful.