I have been embarrassed by some of the things I used to "know". What I've come to "know" is, that I know nothing. There are things I can experience with the senses, but they can be fooled. There are things I can try to disprove with the scientific method and then accept the results. There are several things I believe in. There are things I have faith in, and hope for - but in the end, I know that I know nothing. I think people confuse "knowing" something with deciding something. It's super easy to believe that the earth is six thousand years old. You just decide it, and stop accepting notions to the contrary. It's much easier to "know" something when you don't even entertain contrary arguments. I can't do that though. I don't like being a fool. I really hate feeling stupid (I've had years of experience doing this).