At 90, Dick Van Dyke has not lost an ounce of the charm, humour and joie de vivre that propelled him to global stardom in 1964's Mary Poppins. Neither does he seem to have tired of discussing his character Bert - the all-singing, all-dancing chimney sweep - and his rather dodgy cockney accent.
"Judi Dench, Helen Mirren and Jeremy Irons were asked who did the worst British accent in the history of the cinema and, of course, I won hands down," he says with a chuckle.
"I wrote them a note and said, 'It's nice to be number one!' But the funny thing is, I was working with a cast of almost all Brits, and neither Julie [Andrews] nor anyone else ever said, 'You know, you ought to work on that accent'.
"I was so busy with the singing and dancing and having fun that I didn't pay much attention," he adds. "I just told people he wasn't really a cockney, he was from some Northern shire settled by people from Ohio!"
Van Dyke hails originally from Missouri, however, and grew up in Illinois. Today, it's Malibu in California he calls home - which is where he is, munching on a breakfast of bran and blueberries, when I call him for our phone interview, to coincide with the UK paperback release of his memoir, My Lucky Life: In And Out Of Showbusiness.
A true entertainer, beloved by students of a certain age for his long-running daytime show Diagnosis Murder (which also stars his son, Barry), Van Dyke's career began almost by chance during World War II.
At 17, he'd planned to join the US Air Forces but flunked his military exams, which meant he couldn't be a fighter pilot and was assigned to Special Services, putting on variety shows at a base in Texas.
"That was the coward's way out - singing and dancing to avoid being a bombardier - but that was what got me into showbusiness and I decided that I liked it!"
Years of hard graft followed, as Van Dyke toured his lip-syncing act The Merry Mutes, finally making his name, quite literally, in The Dick Van Dyke Show, the sitcom in which he played comedy writer Rob Petrie.
Walt Disney came knocking, attracted by Van Dyke's 'good, clean fun' principle, which he credits for his long-lasting career.
"I've always tried to keep it to family entertainment, and I got lucky enough to be in such good productions with Disney, they've lasted 50 years," he says. "Good family entertainment's rare, and I'm on my third generation with kids."
He's still entertaining families whenever he can. Just a couple of weeks ago, a video of him bursting into Chitty Chitty Bang Bang while having lunch at a diner with his a cappella group, The Vantastix, went viral.
"At the table next to us were about four little kids and they kept staring at me, but were too shy to say anything or do anything. So I finally said, 'Do you want to hear a song?' It was wonderful - everybody in the restaurant joined in!"
His book evokes the Golden Age of Hollywood, with the likes of Fred Astaire dropping in to watch a run-through of his Broadway musical Bye Bye Birdie, and Frank Sinatra cooking him pasta. Van Dyke sought out his two comedy heroes - Stan Laurel and Buster Keaton - and got to know them so well, he ended up giving the eulogies at their funerals.
It's a very different place now, he says: "There is no Hollywood any more. Los Angeles really isn't the centre of film-making, they make them everywhere else. Cinematography has become unbelievable with computer graphics, which they always use nicely, but... the quality of movies... everything's a franchise now, like Star Wars, and the actors become almost interchangeable, with a few notable exceptions, most of them British."
And it's tough to get work over a certain age.
"I think it's worse now than ever. Somebody said the final and last acceptable discrimination is ageism, and it's very true. I know wonderful writers and actors who've passed 50 or 60 and they can't get work, I don't know what it is.
"You look at the sitcoms today and I swear to God, they could just switch the actors around and I wouldn't know the difference."
He's equally vocal on the race for the US Presidency. A lifelong political activist, he campaigned "very hard" for Bernie Sanders, but thinks Hillary Clinton is "all right - I think we'll have the status quo".
Asked whether he could envisage Donald Trump as president, he's incandescent...
"No I cannot! He talks like Mussolini, like he intends to do away with the Congress and just become a dictator. He can't do half the things he's said and he's constantly changing his approach. He's not a politician or a gentleman or anything else," he says, hardly stopping for breath. "They talk about the dumbing down of America - I'm beginning to believe it. We've gone bananas, I can't understand it. These people that can't read that man, it frightens me to death."
He admits he fears for the future of his great-grandchildren, of whom there are many ("They're popping so fast, I can't keep count. I think it's two in the last six months").
Van Dyke dedicates his book to his four kids with childhood sweetheart and former wife of 36 years, Margie. He lived with Lee Marvin's ex Michelle Triola for more than 30 years, until her death in 2009, and in 2012 married make-up artist Arlene.
"She keeps me young," he says, explaining they're currently rehearsing a song and dance routine for a new show with his quartet, and adding the 46-year age gap "doesn't make any difference at all".
Also discussed in his book are Van Dyke's battles with alcohol. He describes himself as the "prototypical social drinker", starting with a martini to overcome his nerves, and ending with him snapping at Margie and the kids after a heavy night. In 1972, with a hangover and bad case of the shakes, he acknowledged he had a problem and checked into rehab.
"I thought that to go public would be the best thing, because so many people suffer from it," he says. "There was such a stigma - I don't think it's quite as bad today as it used to be.
"I don't drink at all (now) and I don't miss it."
Exercise and healthy living are key to his longevity, he believes, and Van Dyke has even written a book on the subject, called Keep Moving, giving advice to the elderly on how to stay active.
"I wake up at six in the morning, whether I want to or not, so I have to have a cup of coffee and go straight to the gym, or I talk myself out of it.
"I say about five times in the book, do not start going down the stairs sideways because it feels good on your knees," he adds. "It'll throw your back out and your hip out and, before you know it, you're in real trouble. So just put up with a little pain."
As for other acting jobs, he's heard about the Mary Poppins sequel, due out in 2017, but isn't convinced about making a cameo if approached.
"I shall tell them Bert is dead," he says, chuckling. "I'm a little disturbed, because I think without Walt (Disney) and without the Sherman Brothers (who wrote the music), it's going to be difficult. And traditionally, sequels really aren't as good. I hope it's successful," he adds.
One ambition he would like to realise, however, is "doing a Shakespeare".
"I'm the right age for King Lear right now," he says with another chuckle.
Perhaps he could come to the UK and play Lear on stage in the West End?
He thinks for a beat, and then says: "I could, yeah, if they don't mind my accent."
My Lucky Life: In And Out Of Show Business by Dick Van Dyke is published in paperback by John Blake Publishing, priced £8.99