The husband of Dame Barbara Windsor has revealed the heartbreaking moment she didn't recognise him as the actress battles with dementia.
Scott Mitchell told ITV News: "The day you dread is for that day they may not recognise you, and I experienced that maybe about two months ago or so and it did happen.
"And she did look at me and say 'I'm sorry, who are you?'
"It was very hard, it instantly hurt, I remember that, and I just kept talking, I said 'it's me Bar, it's Scott', I said 'don't worry you're just having one of those moments.'"
He added: "She got very upset because she realised what she'd done."
Mr Mitchell said it is often hard to hear the actress apologising for not remembering.
"I think the thing that stays with me is she keeps apologising for it and saying I am so sorry about this Scott, I am so sorry, which is an awful thing to hear, for of course no one living with it can help it."
He said there are still smiles and laughter from the actress as: "There are still incredible glimpses of Barbara, we went to see a Pantomime a couple of weeks ago, and when we're in the theatre, she comes alive especially when she talks to the public."
EastEnders cast members reveal to Dame Barbara they are running the London Marathon for Dementia Revolution:
Jake Wood, Adam Woodyatt and Natalie Cassidy are among the soap-stars taking part in the race.
Mr Mitchell said when he gets tired and wants to stop during training for the 26.2 mile race, he pushes himself and thinks of a number of personal circumstances.
"I think of every time I have to explain to Barbara where she is when we're sitting in our front room and she's asking me if we've stayed here before - that gets me through the pain barrier," he said.
Mr Mitchell, who married Dame Barbara in 2000, said he has to remind her regularly that he is running the London Marathon, adding: "But she kind of clicks straight away when I do remind her, and when I tell her the team from EastEnders are doing it, she's just thrilled."
They are hoping to raise £100,000 to help fund ground-breaking research into dementia, as well as boosting awareness of the condition.