The pop star deferred her music career to take a History of Western Civilisation course two summers ago at the University of California, Los Angeles and was able to sit in classes without causing a stir by swapping her glamorous stage outfits for loose-fitting men's clothing.

"I went to university after my last tour and studied history. I lived the regular student life for a bit. I used to wear a cap, tennis shoes, big backpack, baggy pants - I looked like a boy. I tried to hide and concentrate on my classes," she said.  "It was one of those things that had passed me by. I would have liked a normal career and to have experienced normal student life - but I'm not complaining," she added.