Janet Jackson: I'm off my trolley

She is reportedly the ninth most successful pop artist on the planet, with a £75 million fortune, but does that really excuse not knowing what a supermarket trolley is?

Janet Jackson is apparently so detached from reality that, while out shopping with r'n'b pal Missy Elliott, she thought a trolley - or cart as it is known in the US - was a scooter and rode it down the aisles.

The 40-year-old was also stumped by a 'square thing' at the checkout - the chip and Pin credit-card reader.

In fact, she did not even know you could pay by credit card at a supermarket.

Jackson told V Magazine: 'I haven't set foot in a grocery store in years. And that's so embarrassing.

'I kept going "What's this?". First of all I had the cart and I was riding down the aisles, standing on it. And we got to the checkout and there's this square thing and I'm like, "What's this, you guys?".

'They said, "That's so you can use your credit card. And I said, "You can use your credit card in grocery stores now?" Missy just cracked up laughing.'