Literal Meaning
When you’re training as a teacher, you’ll often be told by mentors that you should never be too sarcastic with the things you say to the students. It’s not just because some kids may not get your sarcasm, but it’s also because some of them might take what you’re saying as literal.
The worst part is that you can’t punish a kid for doing this, as you totally brought the mistake on yourself! Technically, this Reddit user didn’t actually do anything wrong, and it’s the math teacher who should’ve been in detention. They should’ve known better than to say something like this!