In a smart bar in Clerkenwell, he explained, with a touch of awe, that he had visited Oxford, where the kid from Brooklyn found himself lionised by dons and local authors. How could I begin to reply?
Here was a writer born to immigrant parents who, with no advantages of birth or status, had imprinted his singular vision on the minds of millions of grateful readers all around the world. Yet he still cared deeply about the good opinion of the limey literati amid their slumbering spires.
Heller never stopped trying and (at some level) never quite believed his luck. Even the sure knowledge that he written one of the small handful of novels that will define the 20th century failed to supply the ultimate security that (as his books show) we can never hope to possess.
He had recently been working hard on a follow-up to his 1997 memoirs, Now and Then, and, always happy to meet his readers, came to the Cheltenham Festival in October.
"He was the antithesis of the reserved writer," said his UK publisher Martin Fletcher, editorial director at Simon & Schuster. "He was a delight to work with, and was always so grateful for anything that anyone did for him." A hard-driving edge - and a sense of wonder that he had come so far - never deserted Heller.
The message that no mortal can ever just sit back and relax emerges not just from the paranoid world of Catch-22 but from the often undervalued books that followed: in the corporate and domestic horrors of Something Happened and Good as Gold, and the comically metaphysical angst of King David in God Knows.
In the 1980s, Heller suffered an obscure paralytic illness. Characteristically, he re-shaped this mysterious blow of fate into a sparky and challenging book (co-written with Speed Vogel), No Laughing Matter. Except, in Heller's hands, it was.
The central conceit of Catch-22 (originally entitled Catch-18) made him the wise-cracking, yarn-spinning Kafka of the Coca-Cola generation.
Of course, the book's razor-edged comedy reflects a young airman's harrowing ordeal in Italy in the latter stages of the Second World War.
Its pioneering portrait of an absurd bureaucracy that shelters and destroys its pawns became the finest fictional paradigm of life in late 20th-century institutions.
Yossarian, patron saint of the awkward squad, sustained his revolt against the system. So did Heller.
Yet he, and all his readers, knew that it was the archetypal spiv, Milo Mindbender, who had inherited the earth.
In a world of ruthless Cathcarts and smarmy Mindbenders - at school, at work, at home, in politics - Joseph Heller gave two generations the courage and the wit to dissent.