At 9 a.m. I look down and catch sight of my left foot - an orange sock! Not a good match with today's pink shirt. An irritating mistake but hardly the end of the world. Who'll notice in any case?

Midday and a student asks why I'm wearing different coloured socks. Yes, I say, I know - orange socks and a pink shirt don't go.

He corrects me: no - it's not orange socks (plural) but sock. The right one is pink.

I hadn't noticed and simply assumed they were both the same. To make matters worse one is patterned with bees, the other zebras. A sartorial disaster. (Or 'faux pas' I suggest hoping for a laugh from the French speakers.)

It goes to show the dangers of fumbling for a pair of socks in the half-light of the bedroom at 6 a.m..

One lives and learns. And wears socks.