Neither are your "true preferences" - but preferences changes lead to self-defeating behaviour. If you put your vodka in the loft in the morning to prevent yourself drinking it, and then get it down again in the evening when you change your mind, that's two trips into the loft whose only purpose is to counter each other, which is wasted effort by any measure. Whatever you value, it has to make sense to "straighten out" your preferences so you're not fighting against yourself.
Just saw this article on reddit and thought it would be relevant here: Self Control is Contagious, Study Finds
Apparently seeing other people exhibit self control or even just thinking of them tends to increase (or decrease if observing poor self control) one's own self control.