David McCallum has heard this story before.
But ever the gentleman, he listens intently as a female baby-boomer relates how he made her pre-teenage heart skip more than a few beats as the blonde, blue-eyed Russian-born secret agent Illya Kuryakin on the 1964-68 espionage series The Man From U. N. C. L. E. Kuryakin and equally sexy American spy Napoleon Solo (Robert Vaughn) worked for a secret government agency called the United Network Command for Law and Enforcement.
Its nemesis was the evil T. H. R. U. S. H - the Technological Hierarchy for the Removal of Undesirables and the Subjugation of Humanity.
The youthful-looking and charming actor, who turns 76 last month, recalls that "U. N. C. L. E-mania" was so great that one day three mounted policemen had to escort him out of New York's Central Park.
"I just went for a walk," says McCallum.
"I was staying at the Plaza [Hotel] for the weekend and literally had to be hoisted on to a police horse and taken out."
The long-running action series NCIS has brought McCallum even more fame.
McCallum plays the eccentric Dr Donald "Ducky" Mallard, the chief medical examiner who has seen it all.
Ducky frequently uses his psychological training to help the team understand clues left by the killers.
He describes the series as "the little engine that could", despite his belief the show has not received the recognition it should.
"We never had a feeling that they [CBS, which produces the show] were throwing everything they could behind us to make us more of a success," he says, relaxing in his trailer on the set of NCIS.
"We just did it on our own, with sheer guts and hard work."
The actor is celebrating his 63rd year in the business.
He began performing plays on BBC Radio where his father, David McCallum Sen, principal first violinist with the London Philharmonic and Royal Philharmonic, also worked.
McCallum went to the Royal Academy of Music where he played the oboe - which he still plays - but realised after a few days with the senior orchestra that he wasn't good enough to keep up with the group.
So he turned to theatre.
He briefly attended the Royal Academy of Dramatic Art and later became stage manager at a repertory theatre in northern London before joining the Army.
Upon his discharge, he went back to London, where he had been promised a stage manager position at a theatre.
But when he learned of the paltry wages, he went to the Oxford Playhouse, where he focused on acting.
While shooting 1963's The Great Escape in Europe, the film's director, John Sturges, allowed him 10 days off to visit Los Angeles to test for the role of the apostle Judas in George Stevens' 1965 epic The Greatest Story Ever Told.
"My first encounter with America was driving a white Chevrolet with a red interior down Sunset Boulevard listening to the Supremes on the radio and saying, `What took me so long to find this place?'
"And miracles of miracles, I got the part."
