Onetap has brought this to us :
My Mum thought the electric leaked out of 3-pin sockets that were left
switched on with nothing plugged in. I pointed out the little plastic
shutters on the L & N pins that stopped the electric leaking out.

She grew up a long way from mains electricity.

My other half insists on turning the switch on a socket off, before
unplugging. She seems never to have come across unswitched 13amp socket
outlets.