Tell him the key signature has 8 sharps.
or
You'd be annoyed if you opened it and a socket set fell out!"
or
Meat and Democrats!
or
Because it's pretty basic stuff.
or
"because," he said "I can't stand chess nuts boasting in an open foyer."
or
What's a light bulb?
or
It saves time in the long run.
or
they just stop reacting.
or
A computer mouse.
or