Pop star Pink was shocked her latest single So What shot to the top of the U.S. charts - because she didn't think her fellow Americans understood her wild ways.

The feisty singer scored her first number one single in America with her love/hate anthem last week, despite being on the music scene for eight years.

And the star doesn't understand how the track found its way to the top spot - insisting music fans in the U.S. think she's a "psycho".

She says, "No one could believe I was number one. They still think I'm a psycho. I just laugh and don't pay much attention, I guess I'm pretty much all over the place.

"I'm pretty in your face and that can work against me. People still don't get me."