What d'you mean you're washing your hair?

I was walking to work one morning when I saw some boys smashing up the toys in the garden of the nursery next door to the school. I was outraged by this act of vandalism and immediately resolved to do something about it.
"Stop doing that!" I shouted, "Those toys are for the little children and they'll have nothing to play on if you break them into bits."
"Fuck off!" one of them said.
The rest ignored me, they just carried on with their destruction.
"But think of the little children," I said, "at least find something else to vent your anger on."
They stopped.
The one who had told me to fuck off said: "You're right."
Then they started to beat me up.
"Stop it!" I pleaded.
"But think of the little children!" they all laughed.