My 10-year-old has been strangely interested in the Cartesian coordinate system lately. Today in the car, he asked if there was an x and y coordinates for where we are on the planet.
So I'm explaining latitude and longitude to him, and after explaining the concept, I say to him, "For example, right now, we're probably somewhere around 90° west and 30° north."
My wife turns to me and says, "how could you possibly just know that?"
"
I don't know. It's just a thing I know. It is a very rough approximation."
Turns out my guess was about 5° too far east, but only about 0.1° too far north, and I think that's pretty close.