This morning I was frustrated to find that the entry gates at the local railways station were blocked by milling commuters. One woman kept touching her Oyster card to the reader and it kept beeping back to her without letting her through.
In some impatience, I said, 'Wait till the light turns yellow.'
'I did,' she said, 'And it turns red.'
I reached across her to brandish my Oyster card at the reader, just as its indicator light flashed yellow.
It turned red. So did I. The gate remained resolutely shut.
The woman grinned at me.
'That will teach me to pontificate,' I said.
We stood there alternating Oyster cards at the reader while the queue behind us grew and grew.
'Oh dear,' I said, and moved to another line.
Just then the gate opened and the woman nipped through.