Everybody keeps ruffling each other's hair

I first saw it at the zebra crossing. A man took off a lollipop man's hat, smiled, and ruffled his hair. On TV that night the newsreader did it to the weatherman, and two rugby players did it to each other at the end of the game.
"Everybody keeps ruffling each other's hair. I said.

The overweight girl that works in the newsagents did it to me when I bought my paper the next day. A stranger did it when we passed each other in the street. My taxi driver did it when I paid him the fare. The single mum did it to the man selling the Big Issue.

I haven't ruffled anybody's hair, I did loosen my fingers when I saw an old man by the Pick n Mix but I decided not to. He had hair like Art Garfunkel.