I was about to set off for school. We were due to sing Santa Lucia in our music class. But I felt off colour: full-blown (boy) flu was sure to strike. And HTV’s courtroom drama, Crown Court, was on tv after the lunchtime news. (I didn’t mention this to Mum…) A sick note was prepared, and I looked forward to a lazy day at home.

Mid morning, the news came through that the Prime Minister had resigned. Harold Wilson – barely 60, and just two years after returning to Downing Street – was stepping down. It was the shock of the year. (Apart from second division Southampton beating hot favourites Manchester United in the FA Cup Final. And possibly the Wurzels getting to number one with ‘I’ve got a brand new combine harvester’…)

Wilson said later he never intended to stay more than two years. Later, insiders suggested the PM knew that his mind was going, an early sign of the tragic impact of the Alzheimer’s disease that would kill him. But on 16 March 1976, the nation was stunned.

Three decades on, Wilson is unique. The only PM in living memory who has chosen to go. All his successors have been forced out by election defeat or internal rebellion. Tony Blair could learn a useful lesson from the last Labour leader before him to win an election.

(For the record, Wilson actually won four polls to Blair’s three, though 1966 was the closest he came to a landslide!)