I do not remember exactly which podcast I heard this on, but the idea is that making 100% on a decision is easier than going 99% on it. 99% leaves room for doubt and consideration, whereas 100% is a hard-no and there is no internal mental battle to be had. For the rest of the year I am 100% no on alcohol. Easy choice for me. No consideration. It simply is not conducive to my current goals. But if I were to tell myself "I will mostly not drink this year" then there is doubt, consideration. I allow myself the leeway to do it under "certain" undefined circumstances. Being 100% on some of our choices is simply just easier.