Ever since I was a child, people have been commenting on how young certain groups of people are, or how young they look. It started with observations about policemen, and possibly a single comedian on TV asking, “Have you noticed how young policemen look these days?” It became a cliché: policemen look younger than they used to. More accurately, the people making this observation are older than they used to be.

By the time you are in your 30s you will meet many professional people who are younger than you: doctors, lawyers, teachers, all doing proper grown-up jobs. I remember going back to my old school when I was in my early 30s. I had kept in touch with my old form teacher (who had also been my French teacher) and he offered to show me round (there had been a few changes since my day), and to have lunch in the teachers’ dining room. While we were eating, he introduced me to one of the new teachers.  He had joined the school the previous autumn, straight from university. He didn’t just look young, he was young, nearly 10 years younger than me. He would have been 9 or 10 when I went to university and now here he was teaching 6th-formers. I had never said that thing about policemen looking young, but I was tempted to say it with regard to schoolteachers. Within a year I had met, for the first time, a Catholic priest who was younger than me. He was serving in a nearby parish. Since then, rather than referring to policemen, I have been more likely to say, “Have you noticed how young priests are looking these days?”

Public life is filled with people who were born after me. Most MPs are younger than me. Two of the last three UK prime ministers are younger than me, though we were all born in the 1960s. So too was Barack Obama, but he at least is older than I am. This means that there has never been a US president born after me. The current incumbent and Obama’s two predecessors were all born in 1946. Every recent Pope, and indeed every Pope going back for centuries, was older than I am now when they became head of the Catholic church. John Paul II was 58 when he was elected. Still some way for me to go.

I have been reflecting on all of this because of last week’s guest on “Desert Island Discs”, Sonita Alleyne, the new Master of Jesus College Cambridge. She was born some years after me and is the first Master of an Oxbridge college that I know of for whom that applies. Heads of colleges are mostly known as Masters (whether male or female) but other names are used, including President, Principal, Provost and Rector, depending on the institution. I still think of them as being from an older generation. The current head of my old college, who was appointed last year (and also featured on “Desert Island Discs”, in this episode) was, reassuringly for me, born in the 1940s. The other high-profile college appointments that I am aware of were all born in the 1950s, including former Archbishop of Canterbury Rowan Williams (Master of Magdelene Cambridge), former Labour MP Chris Smith (Master of Pembroke Cambridge) and former Guardian editor Alan Rusbridger (Principal of Lady Margaret Hall Oxford).

I see that Wikipedia has lists of the current heads of Oxbridge colleges (Oxford is listed here, and Cambridge here). I am tempted to go through them to see how many colleges are now run people who were born after me. Even it turns out that there are only one or two of them, I have found a new way of commenting on the passing of time. Never mind policemen, priests and teachers. Have you noticed how young Masters of Oxbridge colleges are these days?