That looks to be a strawman. I am sure you can find on TV, but I am unaware of anyone reasonably serious holding this view.
:shrug: That's what I believed. Anyway, your response is a bit of a True Scotsman argument. If I find 100 people who expressed similar beliefs, you can simply dismiss them as not being "reasonably serious."
Let's do this: How do I know if someone is "reasonably serious" or not?
your response is a bit of a True Scotsman argument
In the same way saying that no one serious believes in perpetual motion machines is also a True Scotsman argument.
How do I know if someone is "reasonably serious" or not?
Has adequate knowledge of human physiology and is not trolling :-P
What is something you used to believe, preferably something concrete with direct or implied predictions, that you now know was dead wrong. Was your belief rational given what you knew and could know back then, or was it irrational, and why?
Edit: I feel like some of these are getting a bit glib and political. Please try to explain what false assumptions or biases were underlying your beliefs - be introspective - this is LW after all.