The mystery was finally solved. Les and Joy Milne had come to their first Parkinson's diseaseA condition which affects the part of the brain controlling movement. support-group meeting. "I walked into the room," says Joy, "and I thought, 'SMELL!'"¹

The scent of Les's body had been one of the things that first attracted her to him: "He had a lovely male muskA substance with a strong sweet smell that originally came from Musk deer. It is used in perfumes. smell."

But when Les was 31, he started giving off a "nasty yeastA tiny fungus that can change sugar into alcohol and carbon dioxide. It is also used in bread-making. smell." And his behaviour began to change: "He was more moody. He wasn't as tolerant."

By 45, he seemed a completely different person. Finally, a doctor told them Les had Parkinson's.  

At the support group, Joy realised that everyone had the same "greasy, musty" smell. It was a vital discovery: a chance to catch the disease early.

Joy and Les told a researcher called Tilo Kunath, who arranged an experiment. He gave a group of people new T-shirts to wear in bed. Some had Parkinson's and some did not.

Then he asked Joy to smell the shirts and tell him which ones were from patients. "She was incredibly accurate," he says.

Kunath worked out which chemicals produced by the skin caused the smell. Now a test has been invented to spot the disease in three minutes.

Other people have powers that seem superhuman. They range from Thai Ngoc, a Vietnamese man who has not slept since 1973, to Wim Hof, the Dutch athlete known as "The Iceman" because of his ability to withstand cold.

Jo Cameron from Scotland never feels pain. Rebecca Sharrock from BrisbaneThe third-largest city in Australia, situated on the east coast. remembers everything that has ever happened to her.

American Scott Flansburg can solve maths problems so quickly that he is known as "the fastest human calculator".

But superpowers can have drawbacks. Psychologist Justin Feinstein worked with a woman who felt no fear. As a result, she could find herself in dangerous situations without realising it. "I wouldn't wish it upon anyone," she said.²

Yes: We can all do extraordinary things if we train our minds and bodies in the right way. Tibetan monks can raise their body temperatures to withstand intense cold just by meditating.

No: Most "superpowers" result from genetic mutations or damage to particular parts of the brain. Only a very small number of people in the entire world are likely to experience these.   

Or... It all depends how you define "powers". Everybody is good at something, and in some cases it is obvious from an early age. But other people only stumble upon their gifts later  and by accident.