"I thought: `Here I am in the stocks. I'm nearly 50 years old and I'm doing this silly play-acting'," he says, sitting down with a sigh of relief and taking a well-earned sip of his drink. "What a life!"
Indeed. But he should take it as a compliment. Wendt only attracts such attention because of his alter ego, Norm - one of the best-loved characters from the most-watched sitcom of all time, Cheers.
The barflies' barfly, Norm represented everything that men aspire to in life: he just sat in a bar all day and all night, drinking from a bottomless barrel of beer and being effortlessly funny.
No wonder his entrance into the world's most celebrated bar was always greeted by the sort of whoopin' and hollerin' usually reserved for the appearance of Boyzone on stage.
But just why did we all fall so head-over-heels in love with Norm; an oversized, idle boozer who by any rational standards was not much of a role model? Five years after the character's demise, the actor who played him so wholeheartedly for more than a decade can now reflect on him with something approaching dispassion.
Dressed down in shorts and a T-shirt with the slogan "Divine One", he causes heads to turn in Damien Hirst's impossibly trendy Central London restaurant, Quo Vadis. (While we're about it, just why does it enhance one's eating experience to be faced with a picture of a man in a suit and tie with an egg instead of a head?).
Wendt gives off Norm's easygoing air of someone whose philosophy could be summed up by the phrase: "Life's too short."
In Wendt's eyes, "Norm was the least offensive character - except to Mothers Against Drunk Drivers. The thing was, Norm never really got drunk. There are a lot of men who would love to be able to drink that much with impunity. You had the feeling that he'd always rather have just one more drink than do anything else. He was the prototypical slacker - that's why he was so popular.
"But look at the reality: he was terribly overweight, he couldn't hold down a job and his marriage was a mess. Still, if more barflies had award- winning Hollywood writers at their beck and call, they'd be popular, too."
Paradoxically, it is Norm's very popularity that has made things occasionally sticky for Wendt since Cheers ended. Initially, everything seemed hunky- dory. He was sure it was right for the series to quit while it was ahead, after 11 chart-topping seasons.
"It was a hard call. It seemed initially to defy logic because of the job security, the quality of the work and the fantastic salaries, but it was absolutely the correct decision. Ted [Danson, who played Sam, the barman and leading character] is a really smart guy, and he made a gut decision. He was six months ahead of the public and the critics, and that's a good thing. You always want to leave them begging for more."
So, at that point, Wendt was apparently in a no-lose situation. He had played the best-loved character in the best-loved sitcom in the history of the universe (if you want to see why, you could do worse than wallow in the Cheers Weekend on the Paramount Comedy Channel on 19 and 20 September.) How could he possibly fail?
In the event, quite easily. First, a spin-off series starring Norm was proposed, but "it was quickly rejected. The writers had a hard time making Norm the protagonist. They didn't see him as proactive." Then he had his own vehicle on CBS - called, with stunning inventiveness, The George Wendt Show - but that was pulled after just five episodes.
"The network expected the show to be their saviour, and it didn't work out. We had all the elements, and it still failed. That happens over and over. The question is: how does any sitcom work? There are a zillion ways it can fail. It's like winning the Lottery.
"The only thing is when it goes down in flames and it's called The George Wendt Show, it seems harsh. I almost got the blame. But I'm a big boy."
The success of Frasier - one of Cheers' least effective supporting characters turned into a blinding lead in a spin-off series - must have made that all the more galling. Like that man in the stout advert, Wendt claims not to be bitter - "Frasier is a great character loaded with hubris" - but all the same it must have been hard for him to swallow.
His problem is that he suffers from what you might call Anita Dobson Syndrome: once actors have been so heavily identified with a distinctive and hugely popular character in a long-running series, commissioning editors lack the imagination - or the bottle - to cast them in anything else.
Wendt is the first to acknowledge the difficulty. "It has been hard for executives to envision me doing something other than Norm. A lot of film- makers thought that audiences would see me as Norm and respond in a prejudiced way that might break the integrity of their film.
"It didn't seem fair. Transitioning from Cheers hurt me a bit, but we've all had problems transitioning. Kelsey [Grammer] may even end up being haunted by Frasier."
Wendt's furrowed brow has certainly been smoothed by his casting alongside Stacey Keach and David Dukes in the new all-American version of the hit play, Art, at Wyndham's Theatre in London.
"It's such an acute play about friendship. It's like a painting; everyone has their own subjective take on it. It resonates, so there's a lot to take home with you. Also, there is no shortage of middle-aged actors who'd be thrilled to play any one of those roles."
Wendt relishes these sort of parts that require a good old-fashioned dollop of character acting. "I'm better used as Third or Fourth Banana. There is the odd role where I could get lucky and do the lead - like Archie Bunker - but lead roles are usually more to do with boy meets girl. How could I do that? It's not acceptable.
"It just so happens that in real life I've met a girl and she's lovely [Wendt and his wife have three young children]. I'm sure most people would be surprised that the fat boy can indeed meet a beautiful girl, but it does happen. It's just that you'll never see it on TV."
When his contract in Art runs out in November, Wendt is going on to play a part in a new movie version of Alice In Wonderland. "You have to guess which part I play," he teases. When I suggest Tweedledum, he gleefully tells me: "No, Tweedledee." He then invites me to venture who might be playing his twin. I get this one right first time: Robbie Coltrane.
Who says Wendt doesn't get great parts anymore?
The Cheers Weekend is on the Paramount Comedy Channel on 19 and 20 September. Art continues at Wyndham's Theatre, London, WC2 (0171-369 1736).