A declaration is not a decision. I would put will and effort into my declarations of “today I’m gonna lose weight and eat properly and exercise” or “tomorrow I begin” but those declarations have no power to effect change. It’s not one gigantic decision. It’s the hundreds or thousands of tiny decisions that make the difference. I can declare all I want to, it won’t make me lose weight.
Although this knowledge isn’t a solution to the problem, it will go far in changing the setting in my brain properly to make those little decisions, instead of making myself immediately feel better for the declarative “decision” then not doing anything about said decision and feeling all the worse off in the end for having made the declaration in the first place. The little decisions in their stead will have a working effect.
The cumulative result of these failed declarations is that I end up feeling powerless to make any decisions for my life, because the evidence shows that these almost invariably fail.
Declarations to self and others are useless and at best give temporary gratification that generates angst in the long run.