The picture was taken on a sunny day in 1968 in the playground at Gospel Oak primary school in north London. I am sitting cross-legged in the front row, wearing a pink and orange flowery mini dress. There are 35 of us and, with the exception of the girl sitting a few along from me who had one Asian parent, we are all white.

From Gospel Oak I went to Camden School for Girls, a state grammar school a mile from where I lived. I have just unfurled a long school photo from 1976. I’m at the back, as I’m by now in the sixth form. Among 700 students, I can see two black faces.

Later, at Lady Margaret Hall, Oxford, it was the same story, only posher. After some digging, I’ve found the matriculation picture and can see myself, wearing my black subfusc hat at a ridiculously rakish angle, trying (and failing) to prove I am different to the mainly privately educated white women who surround me.