Have you heard the phrase "put on your thinking cap"?
The first time I heard it was when I was in kindergarten. The teacher was trying to get us all to think hard about something, and so she said "Put your thinking caps on!" in that cheery way that is known only to those who regularly try to educate children under the age of 6. What she meant was something like this:
A thinking cap, it seems, is an imaginary device that allows you to help focus your mind on things and concentrate. My assumption is that all of the other students understood it in this way as well.
Not me. The first time I heard that phrase, I envisioned holding two bottle caps to my ears to hold in all of my thoughts.
The problem, I think, is that the teacher said "Put on your thinking caps". She pluralized "cap". Makes sense if you're talking to a room full of children, but being an only child and an introvert, did I think about the other children in the room? No! I was trying to wrestle with the absurdity of putting two hats on my head – who would do such a crazy thing? – and decided that holding imaginary bottle caps to my ears was far more logical.
I got pretty good grades in school, though. So... thanks, bottle caps?