I just got some stuff from the gas station, it came to $10.89, so I got $9.11 in gas. The (20 something) girl at the register gave me the strangest look when i asked for that amount of fuel, then she saw on the register that the total was an even $20.
Her look turned into one of (lust and) amazement!
She said: "Wow you're really good at math, that's awesome!"
I felt really sorry for her.
It happens all the time when I give change so I get quarters back too.
I always do the math in my head (before verifying with a calculator when the result is important) to keep sharp.
I feel sorry for these kids.