It takes a fair bit of knowledge and intelligence to realize just how little you know. This is a common feature that one finds in people swept up by pseudoscience and denialism: they don’t know enough to realize that they don’t understand the science.
This is why, for example, it’s fairly common to see cranks challenging evolution by natural selection and Einstein’s theory of relativity. These are simple enough that people can think they get the argument (typically a nonrigorous popularization of the argument), and then when they don’t quite understand some important feature of it, they think they’ve found a flaw in modern biology or modern physics, rather than recognizing it as a flaw in their own understanding.
(And don’t forget to discuss conservapedia on relativity at some point.)