i-am-your-idea
pretty vacant
It isn't just that I believe it to be the case - there is not currently a plausible context in which to doubt it. OK, if there was some secret dentist secretely swapping people's teeth, then the question "do I know that thes teeth are mine?" might have a sense.
But until such a context arises, then it is perfectly reasonable to claim that it is something I know.
a reasonable claim is NOT the same as knowledge!
you could be an mad, old man with no teeth, how would you know?