A PE teacher from Cardiff called Tony is frozen solid after being caught in an avalanche in 1979. There he remains until global heating sees to his thawing and he pops up in the present day, exactly as he was back then. Comedy ensues. This is make-believe, by the way; it’s the premise of Mike Bubbins’ BBC series Mammoth. In the masterful opening scenes, to the sound of Gerry Rafferty’s Get It Right Next Time, we see Tony being scornful, angry, frightened and disgusted by four things that didn’t happen before his big freeze.

He scoffs at a bloke carrying a baby in a sling, gives a charity chugger very short shrift, and jumps out of his skin when a youth on a hoverboard zips past him. But it was Tony’s disgust at a woman picking up her German shepherd’s poo that got me thinking. When did picking up dog poo become the thing to do? Or, put another way, when did just leaving it there become the thing not to do? When did we........

© The Guardian