Philip Hensher: All of us knew Pooky Quesnel would be famous eventually

The student population produced conspicuous figures – famous within the university, and whose future world domination everyone took for granted

Sated on Christmas Day, we settled down for the Doctor Who special – it was something to do with a crashing spacecraft and Michael Gambon as an intergalactic Scrooge. The titles rolled, and about halfway down – it was a small but speaking part – appeared "Captain ... Pooky Quesnel". "Pooky Quesnel!" I exclaimed. "Goodness, that takes me back." "What?" said Zaved. "Who's that? Is she famous?"

Pooky Quesnel ... It takes me back a quarter of a century. Oxford University in the early 1980s was probably as fiercely competitive an environment as can be imagined. Whatever "field" you went into, it was vitally important to make your mark as quickly as possible – sports, journalism, politics, drama. Daunted, I personally did absolutely nothing. The student population produced conspicuous figures – famous within the bounds of the university, and whose future world domination everyone took for granted.

One of these was Boris Johnson, of course, whom everyone seemed to know or claim to know. Michael Gove's arrival as a first-year at my college, Lady Margaret Hall, is etched on my memory – I don't think many 18-year-olds these days turn up at university in a green tweed suit. Later, when I went to Cambridge to do my doctorate, there were more university celebrities. My friend Thomas Ades, the composer, was pointed out in the street as Mahler was in Vienna. There was an unforgettable production in 1988 of Cyrano de Bergerac directed by Sam Mendes with Tom Hollander, Jonathan Cake – then a famous beauty – Nick Clegg and the novelist Will Eaves. The programme for that must be worth something on ebay.

One of these Oxford celebrities was Pooky Quesnel. Her wonderful name – "really Joanna", people murmured – preceded her. You could not venture very far into artistic, musical, literary or dramatic circles without hearing something of her. Many an undergraduate that year came a social cropper by airily mentioning something Pooky had said to them, or implying a closer intimacy than was really the case. She was the Imogen Quest of Cowley, that summer of 1984.

I was very much on the remoter borders of these sorts of circles. Acutely shy at the time, I had turned up to Oxford with my double bass – a good instrument to hide behind. I quickly joined the university orchestra and a couple of other ensembles. My great passion was contemporary art music.

But, as most double bass players will tell you, it is quite hard to walk the streets of a university town with your instrument on your back without excitable strangers asking you to join their jazz group, or to play in the pit band for their production. Even if you are really walking to a rehearsal of the Ligeti Kammerkonzert. We were sparse like that, and conspicuous to jazz-recruiters.

Quickly, I became Pooky-conscious. I glimpsed her, yawning crossly in the English faculty library, though surely not in the lecture hall, and in those nostalgie-de-la-boue-ish cafés in the Covered Market. She always had a little court of admirers, and soon, acquaintances of mine were saying to me "The other day, Pooky was saying ...". One saw her on stage. I forget in what. She was marvellous. There was nothing much else to do in Oxford those days, once you had exhausted the possibilities of the programme at the Penultimate Picture Palace.

Would I play in the pit band for a new production of Cabaret, someone asked. It was going to be done as a cabaret performance, with the punters sitting at café tables wreathed in smoke, or at any rate dry ice. I quickly agreed. I adored the film. "Screw Max!" "I do!" [beat] "So do I!" My suburban heart had thrilled to that exchange, back at home. Of course I would do it.

Pooky, of course, was Sally Bowles. Was there anyone else within 50 miles who could have been considered for the green-fingernailed role? She stomped into the rehearsal room, dead on time, in (if memory serves) an old fur coat and a scowl. Did people kiss each other on greeting then? I forget. I had seen her act before, but didn't know that she could sing – a full-blast jazz singer hurling herself round the rehearsal room from the start. It was glorious, but also very slightly embarrassing if your usual associations with the word "rehearsal" was a punctilious man saying "Second violins, more legato at three bars after D". At the tea break, Pooky approached me and asked if I could play the bass in her jazz band. I admitted that I could not. I had blown it.

Years later, someone who had been in that same production of Cabaret told me that the boy who had played Max – the part of the count whom every other character screws – was Matt Frei, subsequently the BBC's man in Germany and Washington. Could this be true? I don't think I could have told you even at the time. There was no one on stage worth looking at apart from Pooky Quesnel being totally mesmerising in the part of Sally Bowles. "She could have shaved her armpits, though," a friend observed after sitting at a front table. It seemed very unlikely there was anyone at Oxford more clearly destined to conquer the world.

Curiously, it didn't seem to happen, though Miss Quesnel has had a respectable sort of acting career before cropping up in a crucial but minor part on the Doctor Who Christmas special. She sang in a jazz band. Then research shows that she played in single episodes of Holby City and The Bill, and a few more regular slots, including Bradley Branning's mother in EastEnders.

She is definitely not a failure, and clearly gets regular work on television and elsewhere, unlike most actors. My point is really that I never saw someone garlanded with such acclaim and, I thought, with such obvious star power. If you had asked me 25 years ago, I would have thought it unlikely in the extreme that I was going to be in a position to mention her name in print, and if that came about, her name would probably need no explanation to the eager reader.

Some people who you meet young have talent and glory just shining out of them. They achieve it, or, alternatively, they settle for labouring respectably while people no one at the time ever heard of, like David Cameron, take over the world. I wonder how many other brilliant Sally Bowleses there are in the world, making a living.