Sir David Jason describes Covid collapse
Watch: Sir David Jason surprised by BBC Breakfast with clip of his first TV appearance
Sir David Jason has revealed he had "seriously bad" Covid this summer, which resulted in the actor collapsing when getting out of bed one night.
Only Fools and Horses and Open All Hours legend, 82, told BBC Breakfast he was fine during the pandemic until succumbing to the virus in July.
"I got it seriously bad," he said.
"Because all the muscles weren't working, I collapsed and I fell against the radiator... I was so weak, I couldn't get up."
Explaining that he had got up to go to the toilet, Sir David told Breakfast's Jon Kay: "I crawled to the bed. The muscles weren't working and I used the bed to try and stand up so that I could go to where I wanted to get, and also get back into bed, and I couldn't…
"I tried for about a quarter of an hour, trying all sorts of things to stand up so I could walk about."
He attempted to get to the door to call to his wife, but said: "My arms wouldn't work and my legs wouldn't work, so being a very creative and inventive person, I thought, how will I get from here to the door?
"You know when you see a walrus if you watch David Attenborough, and they walk on land, they crawl on land? That's what I did.
"But in order to do that, I had to use my head. So now I'm lying face down on the ground, and in order to get to the door - and the arms really weren't working and the legs weren't working - I was using my head to drag me to the door.
"So just as I got to the door, the door opened... and it was my good lady wife and she managed to help me get back into bed. But later on the next day, I got carpet burns all down on my forehead and across the top of my nose."
Sir David has now recovered and is publishing a book about Christmas, including stories from the making of the Only Fools and Horses festive specials.
m was a highlight of the Christmas schedules from the 1980s to the early 2000s, with ratings peaking at more than 24 million in 1996.
Asked by Kay whether he regrets the fact there are now fewer big moments when people gather round the TV, the actor replied: "I do, yes. Because it's what used to happen in those days and I think it used to help to bring the country or the nation or the viewing public together.
"We can communicate in a very different way today. And I just think it was a sad loss for us all, because it just helped to bind us all. Now we've got so much choice that we don't do that any more."
Only Fools and Horses ended on Christmas Day 2003 but is still such a British institution that Del Boy's distinctive yellow three-wheel car was featured in the Queen's Platinum Jubilee pageant this June.
Sir David said he was tickled by seeing the battered Trotters Independent Trading van in the parade. 
"You've got the great [royal] coach coming down, you got all the soldiers and the horses, and the pageantry. And then you look it up The Mall, and down there comes a funny Trotters van. [I thought] I don't believe this, why is the Trotters van there?
"But it was because it was part of the national identity, if you like, and it did make me laugh and bring a smile to my face. There amongst all of this wonderful stuff that the Brits do so brilliantly, those soldiers with their breastplates all polished and their plumes, there's the Trotters' van, and an arm sticking out going, 'All right pal?'
"Yeah. It did just make me laugh. I loved it."