I had a great aunt. She was the sort of great aunt that you would conjure up if you wanted to invent a great aunt. Always straight-faced, apparently straight-laced, and thoroughly wicked. I remember the exquisite agony of accompanying her, when I was a child, along the Crwys Road in Cardiff, pausing at every greengrocer (in the days when all their fruit and veg were on display outside), picking up an apple or some other fruit to inspect its quality, taking a bite, sniffing with disapproval, shaking her head and putting it back. By the time we got back to her house, she had consumed her full five a day without parting with a penny.

She was the source of all information on my mother’s side of the family, so naturally I assumed that everything she told us was…