If one exercises his willpower a lot†, then one has a progressively harder time doing so again shortly after‡. This is so because willpower is a finite, expenda

If one exercises his willpower a lot†, then one has a progressively harder time doing so again shortly after‡. This is so because willpower is a finite, expendable resource which has to be renewed (through not exercising it). † - for instance, by denying himself bad, tempting things ‡ - gives in to temptation It's not flimsy at all, it just appears to be wrong.