Once upon a time there were two little girls, Rena and Rita, born in Glasgow just a few months apart. They lived in Govan, within 100 yards of each other, started school on the same day and instantly became best friends. Every day they went to school arm in arm and came home arm in arm – except for once when they had a fight. But that was just for one day, and afterwards neither of them could even remember what it was about. They stayed best friends all the way through primary and secondary school until they left to start work at 15. Rita Fraser is second on the left of row 2 with the fringe and glasses, and Rena Marshall is in the front row, second from the right.

They made new friends at work and then drifted apart. One day, nearly 10 years after they’d hugged goodbye at school, they ran into each other in Saint Enoch’s Square. Both of them had got married and had a baby boy.

They agreed to meet the following Wednesday. But that afternoon Rena decided to wash a woollen blanket, and afterwards she ran it through the mangle. Of course it got jammed and she spent a frantic hour trying to free it. Eventually she hurried off to meet her old friend, arriving late. But Rita never turned up. Or maybe she had arrived on time and got fed up waiting. Rena wrote to Rita to explain, but she did not receive an answer, and they never saw each other again.

Rena Marshall is my mother. Now 88, she told me about it last week and it made me ponder the fragility of friendships. I find it sad because it is the story of an (entirely avoidably) wrecked relationship.

I am still in touch with some of my old school pals, three of whom I see very regularly. But there are two in particular whom at various times I called my best friend. I have not seen either for over 30 years and there is no obvious reason for that. We drifted apart, as the saying goes, and I am not sure it is 100% my “fault”. I wish them both good health and happiness; I’d be surprised if they think about me at all. That seems to me to be normal and not necessarily a case for deep regret. All things come to an end. But to lose a good friend because of a silly misunderstanding or a bit of bad luck really is a shame. It is worth giving people the benefit of the doubt rather than looking for an opportunity to be aggrieved.