- I now have information I did not have at the time I made a choice that binds me now.
- I changed my mind.
Whether I believe it or not makes no difference because it contains no information.
As an aside: none of this is supposed to invalidate the experience of people having regrets, or struggling with addictions. If I see a friend getting drunk every night I won't go "ah, yes, they are correctly maximizing their utility according to their own discount rate and inter-temporal budget constraints". They are separate conversations, though, and we can have the kind of conversation where I help you solve problems or the kind of conversation where I just listen to you. They don't tend to mix well.