[codemac]

No, not close enough at all!

They show that willpower comes and goes for many reasons, but it is not a limited resource. You can't "use it up" in the morning, and thinking that way will lead you to actually having less willpower in the evenings even though you could have plenty!

[nl]

> You can't "use it up" in the morning

No, but some things you do can deplete it.

[codemac]

They literally say in the quote your reference that's not the case though, that it's fickle - not a resource you can "deplete".