"[She] just bowls me over. I love Britney," the just-wed Material Mom gushes in the February issue of Elle.
"I want to do nothing but support her and praise her... I mean, she's 18 years old. It's just shocking. I wish I'd had my s- - - together when I was 18.
"I was so gawky and geeky and awkward and unsure of myself. I didn't have a tan. I didn't know how to dress."
Britney — who says she's still a virgin and saving herself until marriage — began to invade Madonna's thoughts morning, noon and night last year.
"We're different — apples and oranges. [But] I became obsessed with wearing Britney T-shirts. I slept in them, as well. It was like I felt it would bring me luck. And it did.
"Britney became my talisman."
Madonna first admitted she liked the curvy teen star when she donned a Britney T-shirt at her Roseland concert last year.
But the 42-year-old pop goddess tells Elle that her obsession with Britney has become all-consuming.
"Can I say that I find it really irritating that everyone beats up on Britney Spears," she adds.
Madonna, who married film director Guy Ritchie last month at a $2 million ceremony in Scotland, says her own longevity in the music biz is because, "I'm like a cockroach. You can't get rid of me."
But the sexy blonde singer says there have been many changes in the pop world since she came aboard — particularly with concerts not being as exciting as they once were.
"I don't see the point of doing a show unless you're really going to make some great theater," she says.
"I'm pretty bored with most live shows I see. I don't want to go and watch someone just stand onstage and play music. I want my senses overwhelmed."
Has having kids — Lourdes, 4, and Rocco, 4 months — changed her stage act?
"It's weird juggling children on your knee while you're in your rhinestone outfit," she tells Elle.
Madonna also says she's not at all worried about all those curvy blondes less than half her age who are riding the charts these days.
"Oh, they'll get old and wrinkled and die, too." she laughs.