This was surely one of the most original excuses ever heard for non-attendance at a gathering.

Ten years ago, I went to a reunion of staff and former pupils from my old grammar school, Harrow County for Boys, which was based in north-west London. The happy centrepiece of the evening was a tribute to a much-loved master, Harry Rees, who was finally retiring after years of devoted service, not only in teaching history but also in staging school drama productions.

I was reminded of my affection for the place when I recently participated in a new documentary series on the history of grammar schools, the first episode of which will be shown on BBC Four tonight.

Like so many other grammar schools that flourished in Britain before they were abolished through a mix of ideology and political folly, Harrow County was a fiercely competitive institution, where all boys were taught to strive for excellence.

Read Michael Portillo's article in the Daily Mail