Owen takes the 1962 train to Harrow

"Why don't you take Owen for a train ride?" suggested Karen. Owen loves trains, so it was a great idea for a Sunday morning outing.

We set off from Amersham, the country end of London Underground's Metropolitan line. The train was older than me: it dated from 1962, the year of the Cuban missile crisis, when Harold Macmillan was Britain's prime minister and JFK America's president. It's some consolation to know I'm still younger than some London tube trains, even if I'm older than David Cameron, the man who's most likely be Britain's next prime minister in the coming days!