He has rooms in the Quad at St Edmund Hall where, for four days a week, he has been fulfilling a role as the college's most venerable student - he's just turned 66, old enough to be the father of most of the tutors and grandfather to the other 175 students.
It has been - and continues to be - a tremendous experience, although he admits there are downsides. It's sobering, he says, to walk through a group of students and be completely ignored, a "biological irrelevance", as he puts it; and though he has been accepted and "adopted" by his fellow members of college, he has experienced some lonely hours after dinner as the youngsters around him geared up for revelry. He tells of one surreally sleepless night as a couple switched from their native English into fantasy Russian as they made love in the room below.
And there's a deeper sense of disappointment running beneath this story - because, inspirational though Oxford is, Brignull probably wouldn't be there if his literary career had taken off. Like many industry legends, it took him years to make a clean break and finalise his divorce from advertising, even though it had long been apparent that he had fallen out of love with it (and it, some would say, with him).
His heyday was his period as the head of copywriting during the golden years at CDP, where he coined, among others, the line: "Heineken refreshes the parts other lagers cannot reach."
But when the golden age ended with Frank Lowe's departure, Brignull's career began to drift. He set up his own agency, Brignull Le Bas, which achieved little of note before being swallowed by DDB. There then followed another spell at CDP before he jumped ship to DMB&B, which he joined as the creative director in 1988. Unfortunately, the creatives there didn't care for his management style and his four years there were an unrewarding struggle. He then spent two years at Abbott Mead Vickers BBDO before resigning in 1994, drawing to a close an advertising career lasting some 35 years.
He left to devote more time to his hobby - creative writing - which many expected would soon become more than a hobby. After all, Brignull was regarded as the greatest master of language ever to work in British advertising and was already reckoned to be an amateur poet of note. But it wasn't to be. The poetry dried up and neither of his first two novels found a publisher. A third is unfinished.
"I wrote too much with my head down," he reflects. He didn't allow himself to see the big picture, and missed the cut and thrust that comes from the input of colleagues in the advertising business. He also discovered that writing books is not the same as scripting 30-second commercials.
It was his wife who suggested that if he couldn't create great literature he should switch to Plan B and fulfil another lifetime dream: studying it.
His home is in Bucks ("38 miles from London, 38 miles from Oxford," he points out, pleased that it sits at the midpoint between current and former lives) and he's comfortably off. "I'm not rich. I can't buy my children houses. I made enough to pay for their education. I can afford to call out the plumber. I don't have anxieties on that score. I had a good run."
He has no contact whatsoever with the industry, except as a sometime pundit for The Guardian. He was never really happy as a freelancer. "I was surprised, after I left, that the phone didn't ring often," he reveals. "But that's the thing about advertising. If you're not in it, they forget you. I'm sure some people think I'm dead."
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