ticklish?

I am a proud daddy of a 12 yr old boy.
He is very imaginative.

The other day he read that
"you can't tickle yourself"

Well, always up for the challenge,
pretty shortly, he was able to tickle himself.

Not to be outdone by anybody,
after sleeping on the subject,

he complained that his underarms were now
feeling like they were being constantly tickled,

even though nobody was even touching him.

Fortunately he was able to get his mind off of the whole thing
by making up a game with his brother and sister where the world
was going to come to an end unless a load of bricks were carried from point A to point B by hand.