Creationism is not a theory. Get your own word for it. A theory requires a large body of evidence. That is not possible for creationism.

" Some people are just so absolutely sure they're right, that they're absolutely certain everybody else must be wrong. It's a phenomenon common to all who see only black and white, no grey."

Very true. No true scientist is ever absolutely sure they're right about anything. No true atheist (not forgetting that we're your invention, by the way) is ever absolutely certain that there is no God. I'm supposed to be one of them thar militant atheists, but I don't know whether there's a God or not, and neither does Richard Dawkins. The people who express certainty are the people of religion. You start your day with "Our Father who art in heaven". No maybe, no quite possibly, no probably. Worse, you teach your children to chant those self-same words of absolute certainty as well, even though you have no evidence that there is either a heaven or a God. It's good to agree, Joe.