Had a bit of a laugh a couple of days ago at the market.
I was running the groceries of a customer over the scanner, and she was grumbling about the two kids she had with her, and how she was going to split them up. I couldn't resist, and suggested that they might split like in mitosis, and then she'd have four kids to deal with.
She stared at me for a second, and I inwardly said "oops," thinking I'd gone over her head.
Nope, her reaction instead was "How do you know what mitosis is?"
Oops in the other direction. She clearly thought that, if I was working in a supermarket as a checker, then I couldn't have much education.
I refrained from telling her that I gradutated from college back in '75. Or that I'd taken early retirement, and that this was a job to a) supplement my income and b) get me out of the house and involved in something. I didn't think she'd understand any of that, since it didn't match her preconceptions.
I just told her that I watch a lot of television.