So now I knew the reasons why I looked nothing like either of my two sisters, and my parents clammed up whenever the topic of genetics came up in conversation.

AP confessed to me that back in 1962 he embarked on an affair with healthcare librarian Sheila Moore in Newcastle. Sheila was now dangerously ill and it was time that I learnt the truth: I was their daughter!

I looked up Sheila’s profile in an online community and could see a family resemblance. What puzzled me, however, was why my adoptive parents were considered suitable candidates to look after an unwanted new-born baby. They were only just married themselves, and my father still a poor student at the time that they kindly welcomed me into their lives.

The first person to whom I revealed my new secret was BP. I told him as we implemented the new University measures to deal with postgraduate students upset with the changes to the academic calendar: placating them with bowls of fresh fruit and ice cream.

The next person in on the secret was AB. We were working on a joint paper at the kitchen table when the Internet went down. It seemed as good a time as any to share my extraordinary news.