Willpower is not a muscle that gets tired; it is more like an emotion.

Drawn from what Nir Eyal said

What this subject means

discipline Doing the work when you do not feel like it: whether showing up is the whole secret, or systems and enjoyment beat willpower.

What Nir Eyal actually said

Do you hold this korrent?Do you also believe this?

Shared subject first, then similar wording. They may agree or disagree.