My mom still thinks her computer will get a virus (all by itself) if she leaves it running when she's not around. Even with my explanations. So she shuts it off completely every time she's done. I can imagine her running a cyber security company and telling her employees to shut down the servers when they leave for the night ;)
And one of the reasons no one competent will allow her to run a cyber security company is that she disregards the advice of people more knowledgeable than she is, not because she doesn't have a deep knowledge of how computers work.
