Few institutions attract myth and mystery like Oxford and Cambridge. In the popular imagination, the process of gaining admission is as arcane as a masonic initiation ceremony. But for two weeks every year the two universities open their great gates - many colleges were designed to look like castles - and the centuries-old membrane between them and the real world is pierced.

Everyone knows of someone, the eternal godson of a cousin, who was rejected for being too state school, too public school, didn’t play enough rugby, too sporty. So, the candidate walks in. “Surprise me,” says the creaking don, and if you don’t throw the chair through the windowset light to his newspapercatch the rugby ball and chuck it back, or whatever the mythical tale stipulates you must do, you don’t get in. If you have a particularly progressive tutor, you might be invited to answer questions, which, lore has it, will resemble the musings of an unhinged philosopher. It’s a dark and mysterious process, shrouded in time and leather elbow-patches. They know what they’re looking for and you’re probably not it.

Depressingly, the legends still have currency. In the weeks before my interview to read history at Oxford I got mailshots from a company charging hefty fees to coach the desperate kids of desperate parents. It offered a book of supposedly authentic questions: what is the most interesting thing about a squirrel? How would I test the difference between butter and Utterly Butterly? What does George Bush have in common with a monkey? What shape is ancient history? I didn’t buy it. But it put the frighteners on me.

The admissions process starts in September; 15 of us at my school had decided to be Oxbridge candidates. (My teachers had first suggested that I apply when I was in Year 11.) We were given help with the application forms and had a mock interview, but we were given no special teaching, which I think is right; there is such a thing as being too prepared.

There’s an extra form to complete after the main Ucas application, and for history you have to submit an essay. I sent an A2 piece on the French R evolution, which my teacher had marked, on the question “How far was Robespierre the architect of his own downfall?” Oxford recently introduced a history aptitude test, about two hours long and sat in school, for which you write what you can “see” in difficult source texts and analyse arguments. I’d expected the test to be hard, and it was. There were a couple of specimen papers available online, but I liked the way that it was coach-proof; the answers could only be your own.

I was called down to Oxford for three days in mid-December. I’d chosen to apply to Queen’s College after visiting on an open day in July; while they weren’t offering an easy ride, the tutors at Queen’s seemed to be honest and progressive about the system. It was freezing in the quads, and mist hung around the clocktowers in perfect floodlight. Term was over so the college was half empty; we stayed in student rooms and ate at long tables before log fires. (The university paid for everything.) There was a fair amount of hanging about, watching DVDs in the common room. I could see the problem; Oxford was never designed to have so many applicants, or be “fair and accountable”. It’s torn both ways, aiming to be acceptable to modern applicants who demand fairness and accessibility, while not losing a past weightier and more secure than the present.

The interview felt a little surreal; after hearing about everybody else’s, finally, here was mine. They were hard questions, but nothing bizarre, and nothing about squirrels or butter. They were sensible, grown-up questions about history. Most stemmed from my class work and the essay I had posted, so nothing unheard of was sprung on me. Often the question was a “how” or “why” on the statement that I’d just made. We talked about what conditions are necessary for democracy, and the differences between Stalinist and French revolutionary terror. I name-dropped a couple of books I’d read for preparation, but the interviewers didn’t seem too impressed; I suppose if your job is to read books then you wouldn’t be.

At one point, after I’d suggested that Stalin’s purges were a kind of democracy, the tutor taking notes turned and smiled at the tutor asking the questions. Was she laughing with me or at me? I smiled back and decided to keep digging. You are, after all, only here once. “What I mean by that, of course...” We moved on to talk about Rousseau’s impact. “Have you read The Social Contract?” the tutor asked. Er, no. “It’s really very easy, you know.” Well, I reasoned, it is on my bookshelf, and I’ve almost started it.

“Hmm...”

I stepped out into the icy sunlight. The half-hour interview had passed so quickly, and after a long build-up - it was six months since the first open days -I felt a sudden hollowness. What do I do now? I wandered around the town, trying not to like it too much in case I wasn’t coming back. My mock interview at school had been much more of a heated debate so I’d gone in expecting a struggle, but in the real thing my interviewers had taken a relaxed, softly-softly approach, musing rather than hammering the answer out.

I wasn’t sure if I’d done my best; perhaps I would have produced something firmer and smarter if I’d been placed under cross-examination. Even that worried me; apparently if they think you’re worth taking then they usually push you as far as you can go until you collapse. So why hadn’t they? It wasn’t hurting, so was it not working?

I soon heard rumours of candidates at other colleges being sat on milking stools in darkened rooms and asked if the walls were made of cheese. But the people I was interviewed with all seemed to meet tutors who showed no interest in old school ties or silly games. Why would they? Because Oxford and Cambridge ask for written work, tests and interviews they have far more information about candidates than most universities, meaning that while they are the toughest on admissions, they are probably among the fairest.

It’s ultimately in their interest to be open and reasonable, and they were.

Then, after 10 days of heel-kicking and running through the interview in my mind, after hoping for the best and quite fully expecting the worst, a couple of days before Christmas the thin letter arrived. I was in, dependent on three As at A-level in history, politics and English literature. Nine other people from my school have got Oxbridge offers, which is the most for a long time. Suddenly, the spires are no longer a dream.

Matthew Holehouse is in Year 13 at Harrogate grammar, a mixed comprehensive with 1,600 pupils, and was AQA’s top GCSE English candidate in 2004. He plans to start at the Queen’s College, Oxford, this October