The thing is, among contemporary British actors, nobody does it better. He delivered a bravura, Bafta-winning crack-up as the megalomaniac left- wing council leader, Michael Murray, in Alan Bleasdale's GBH - which culminated in a nervous twitch resembling nothing so much as a Nazi salute. He gave another marvellously pyrotechnical performance of mental disintegration - writhing on the floor and wailing, "Will no one rid me of this priest?" - as Henry II in Anouilh's Becket. And he tore his hair out to memorable effect as the guilt-wracked adulterer in Bleasdale's Jake's Progress. He's an actor who thrives on extremism.
Any old fool, of course, can wave their arms about and shout a lot on stage - as anyone who has ever seen a school play will testify. What distinguishes Lindsay's mania is its plausibility. His boundless energy is not expended willy-nilly but thoughtfully channelled; he is as physically disciplined as a professional athlete. "He has the instincts of an actor and the abilities of a clown," says Steven Moffat, the writer of The Office. "He can do the prattish stuff without going over the top. He maintains the restraint of an actor. For farce, you need to believe in it for it to be funny."
Paul Jackson, the former managing director of Carlton who directed The Office and whose credits include The Young Ones, concurs. "Bob has the ability to mould a character for you immediately. Within five minutes of the start of The Office, you pick up the fact that he's a nervous executive, but he's perfectly rational, dictating a letter to his secretary. Then one major misunderstanding leads to 15 others. If you believe that, then you're away to the races. Bob is able not only to make nervous disintegration believable, but also - and this is crucial - the character before the nervous disintegration believable. If he'd entered the office a gibbering wreck, it wouldn't have worked."
Jackson reveals that Lindsay puts a lot of work into making his creations credible. "It's a cliche, but he's always thinking about the script," the director continues. "For example, in the striptease scene in The Office, the writer couldn't say any more than 'He gets his kit off'. Bob really thought it through - 'What drives this otherwise sane man to do this?' There's a very long reaction shot before he does it, and you see it registered in his face. That's a pivotal scene, all conveyed through Bob's face."
Lindsay's face is certainly part of his fortune. At 45, he still has an impressive mane of brown hair over a well-preserved visage and lustrous, brown "come into my office" eyes. He looks tanned and fit - he confesses that the gym has been visited (well, he was going to be parading naked in front of several million viewers). "There are actors the camera loves and actors that's not true of," says Sandra Hastie, the producer of The Office. "The camera loves Robert. It gets inside his head so we can see his mind working. Even with a motorbike helmet visor on, he manages to convey emotion. He can show vulnerability and intelligence. If we'd gone with a comedian rather than an actor in that role, you wouldn't laugh as much because you wouldn't empathise as much."
Lindsay himself is embarrassed by all the attention and has to be coaxed into some self-assessment. "The interesting thing is the transition between comedy and drama," he ventures. "It's fantastic to jump the precipice between being funny and dramatic in the same scene. It can be quite dangerous to cross the line and go from one extreme to the other. Even in the scene where I cracked up at the end of GBH, I was still thinking 'laughs'. It was like I was two people." This duality in the actor was spotted by Michael Elliott of the Royal Exchange Theatre in Manchester, when casting for Olivier's Lear. As he told Lindsay: "I don't know whether you should be a goodie or a baddie."
Lindsay was brought up in Ilkeston, Derbyshire, the son of a joiner. He went to Rada in 1968 at the urging of friends on his drama teaching course in Nottingham. His big break came in 1976 when he was cast as Wolfie, the lead role in Citizen Smith, John Sullivan's likeable sitcom about a deluded member of the Tooting Popular Front, which Lindsay now describes as "Men Trying to Behave Badly". For many years thereafter, passers-by would shout out Wolfie's catchphrase - "Power to the people!" - as Lindsay went by. (Similarly, for some time after GBH, people would start to twitch maniacally on seeing him in the street.)
In 1985, Lindsay displayed his versatility by wowing both audiences and critics (he won an Olivier and a Tony) as a song-and-dance man on both sides of the Atlantic in the stage musical, Me and My Girl. It presaged the one wobble of his career. "I was being offered almost everything when I did that show," he recalls. "With hindsight, I should have come straight back here, gone off to the National Theatre and re-evaluated my life. But I got carried away on the tide of success and just grabbed the first thing that came along."
That was an ill-fated Hollywood movie called Bert Rigby, You're a Fool. "It was obviously the wrong thing," Lindsay reflects. "I was playing the film star. I'd forgotten the script and become obsessed with the size of my Winnebago. I kept asking my driver to go through the studio gates again, and I was completely overawed by the fact that there was champagne in a cool-box every morning. All day on the set I took pictures of the chair with my name on."
At least he avoided the traditional Hollywood vices of wine, women and song. "I didn't have time for them," he laughs. "I was taking too many photographs."
The finished film "never saw the light of day", Lindsay sighs. "I always remember one review which said, 'It's sad to see Robert Lindsay being run over by his own vehicle.' One of those wonderful bleak Sunday afternoons it's going to be on BBC1. It had a premiere in London, and I was in a Chinese restaurant opposite, watching all six people go in. I don't regret it now. It brought me back down to earth. It was a good lesson. I'd started believing the press after Me and My Girl."
Ah, yes, the press. Lindsay has been on the receiving end of several unpleasant bites from the rat pack. "I've always been open and generous with the press," he maintains. "I've been through ups and downs domestically, but that's for me to deal with. When the press interfere, it suddenly becomes something else. You think, 'That's not public, that's very private indeed.' It's the English mentality. We don't like success. We build people up and knock them down."
Soon to appear on our screens in Michael Frayn's suburban comedy, Remember Me?, Elijah Moshinsky's brothel drama, Brazen Husseys, and Granada's euthanasia drama Act of Love, Lindsay looks set to remain a tabloid-baiting success. Viewers like him and so do producers.
Hastie provides a reference to satisfy any potential future employer. "Robert has a great understanding of humanity," she enthuses. "We all have times - almost daily - when we're on edge, and Robert can convey that wonderfully. His range is enormous. One of the problems with comedy drama is to find an actor who can get the pathos as well as the comedy. Robert is one of the few who can. Before his life on this planet is done, I hope he does Lear."
Ending the hero-gram with a flourish, she adds: "And he never once asked for a Winnebago."
The Office is on ITV at 8.30pm tonight