Onstage, Roger revealed that Dame Judi never got to grips with the leading lady's odd views about hospitality; that he auditioned for the RSC on this very stage in 1965; and that he never really knew his father, an absentee Welsh policeman, which explained a lot about his Hamlet.
He then stuck a baseball cap on his head, back to front, and became the Nurse in Romeo and Juliet, suddenly resembling a rather fey navvy played by Robert Downey Jr. That was one of two very sharp moments in an otherwise soupy, self-indulgent ramble through some over-familiar Shakespeare speeches and reasonably well known anecdotes.
One I'd not heard before provided the other sharp moment. Vivien Leigh played Lavinia in Titus Andronicus and ruined the scene where - having been deprived of her tongue and her hands - she carves the names of her enemies in the sand with a stick held between her bloody forearms; one night, the stick slipped down the lacerated flesh and shot into the front row of the stalls.
Noel Coward visited her backstage afterwards and delivered a one-word review as he put his head round her dressing room door: "Butter-stumps!" Roger failed to elaborate on this comment with Kenneth Tynan's notorious, only slightly less brief, comment in his printed notice: "As Lavinia, Vivien Leigh receives the news that she is about to be ravished on her husband's corpse with little more than the mild annoyance of one who would have preferred foam rubber."
Needless to say, Laurence Olivier - Leigh's husband both on and offstage at the time, playing Titus - was less than delighted with that review and never forgave Tynan, even though he was persuaded by his next wife, Joan Plowright, to hire him as his literary manager at the National Theatre a few years later.
"Better to have the little bastard on the inside pissing out than on the outside pissing in," was his weary way of accepting the logical excellence of Plowright's suggestion.
Each member of the Apollo audience was handed a reproduction of the John Vickers photograph that determined Roger to become an actor: it's of Ralph Richardson as Falstaff in 1945, heaving the body of Olivier as Hotspur from the field at Shrewsbury in order to claim that he has killed him.
Why this picture should have had such an effect is a mystery to me. It's dull and lifeless, palpably posed, and the painted backcloth showing "Shrewsbury clock" a testament to the poor standards of theatre design at that time.
Again, Tynan could have helped Roger out more effectively. In his book, He That Plays the King, the great critic (then in embryo) devotes two pages to Richardson's performance in the course of arguing that Richardson and Olivier "summed up" English acting in themselves.
"He was Sir John first," said Tynan, "and Falstaff second, and let every cock-a-hoop young dog beware. The spirit behind all the rotund nobility was spry and elastic: that, almost, of what Skelton in a fine phrase called 'friskajolly younkerkins'; there was also, working with great slyness but great energy, a sharp business sense: and, when the situation called for it, great wisdom and melancholy..."
While making a film called The Ebony Tower with Olivier in 1983, Roger recounts an extraordinary thing the great star did: he took each and every one of the cast and crew to dinner, one by one, night after night.
On Roger's night, their drink at the bar was interrupted by a phone call. And Olivier simply said: "Oh Roger, Ralph's died." And that's the end of the story. No ceremony else? We shall never know if the two of them had their dinner, or how Olivier coped thereafter, or indeed what Roger said to him.
What we do know is that Richardson was, and remains, one of Roger's four favourite actors. The others? A 19th century bit player called Mr Cubitt who was happy playing walk-on roles and flunked a big chance when it came; David Garrick, with his startled pop-up wig effect for the ghost-in-the-boudoir scene; and "for reasons it would take too long to explain," Harvey Keitel.
See what I mean? How frustrating is that? The sooner someone gets interviewing Mr Rees in full and unexpurgated depth, the better.