When I say belief, than I mean stuff that's in your mind and that effects the way you act. The question "What do I believe?" is a different question than "What's resonable for me to believe?".

I never consciously formed my "Tuesday -> Wednesday but not Tuesday->Monday" belief. I just noticed the belief when I got it challenged. It produced a lot of stress. The fact that I can know intellectually that my memory isn't perfect doesn't change the fact that I belief on an emotional level in my memory.

It might not be the best example because a lot of people don't have similar experiences of how it feels like to get such a belief challenged by empiric reality.

Then let's take a different belief from the world of social dynamics. A guy who thinks no girl likes him because he's fat doesn't suddenly drop his belief when you show him fat guys with girlfriends. It takes emotional work to change the belief.

If you just have a computer program with values in it, then I don't think you can reasonable say that those values are what you belief if you haven't actually integrated those beliefs in your mind.