Dame Vera Lynn said she could not believe she had turned 100 - but that "time marches on" - as she celebrated her landmark birthday.
The Forces' Sweetheart, whose image has been projected on to the white cliffs of Dover, became a centenarian on Monday.
She told the Chris Evans Breakfast Show: "When I look on my mantelpiece and see these cards wishing me a happy 100th birthday I can't believe it, but there you are, time marches on.
"And this is what I have got up there on my mantelpiece, to remind me of how old I am."
Remembering the early days of her career, she laughed: "I remember very clearly, when I first sang to the boys, I was just told to go on a stage dressed in a pretty dress and sing a song, which I did.
"The people wanted an encore so I would go off, take that dress off, and put another one on to go back to sing a second song.
"They don't do anything like that now, change their dress for each song they sang."
Asked if she had any advice on getting older, Dame Vera, who made her stage debut at the age of seven, offered: "Be active to your full capabilities, keep interested, read books, watch television and try and keep in touch with life and what people are doing, seeing and enjoying."
Talking about her work to entertain the troops and boost morale, she said: "It was wonderful to be able to do something in those times" and she added: "I'm glad it helped them to hold on to home."
The 350ft image of the singer, famous for songs such as The White Cliffs Of Dover and We'll Meet Again, was commissioned to mark Dame Vera's 100th birthday
It is also a celebration of the release of her new album, Vera Lynn 100, which features re-orchestrated versions of her most beloved music alongside her original vocals.