I suspect that with enough resources you could be talked out of any of your beliefs.

At some point you have to ask: who is this "me" that can have any arbitrary collection of beliefs?

(And yes, incidentally, I don't assign 100% probability to the fact that I assign 100% probability to the statement "0 and 1 are probabilities." I think I could be persuaded, not to have a lower confidence in the 0-1 statement, but to believe that my confidence in it is lower than it is. This is sort of hard to think about, though.)