I met my new young man back in 1975. He squeezed into the seat next to me on one of the first 125 trains released into the fleet. We agreed to meet the next day beside the cave. He didn’t mention his wife and child, nor did I make any reference to my boyfriend.

As a time-traveller from the twenty-first century I had so much to tell. I started with the concept of e-mail. To set the context, I first explained e-mail’s impact on the ancient practice of memo-writing and the role of secretaries.

Then, upsetting the man somewhat, I revealed that the first marriages of Prince Charles, Princess Anne and Prince Andrew all ended in divorce.

My last piece of intelligence was that poor Michael Jackson died aged just 50. This name meant nothing to my companion at first. It didn’t register with him that the little boy who had enjoyed chart success with Rockin’ Robin just three years earlier in 1972 would die an international pop sensation in June 2009.