By Sheena McKenzie, for CNN
London, England (CNN) - Not many people would see quadriplegia as a gift. But then, not many people are Paul Callahan.
As a 21-year-old Harvard University student, Paul's life was full of possibility. An undergraduate studying business at one of the best universities in the world, there was a lot to look forward to for the young man from Massachusetts.
Then a freak accident changed everything. Paul slipped on a wet floor, breaking his neck and rendering him paralyzed from the chest down. He retained the use of his arms, but not his hands.
Callahan spent the next five years traveling to rehabilitation centers across the United States in search of a way to walk again. When a doctor finally suggested it was time to concentrate on living instead of walking, Paul did exactly that.
Almost 30 years later, the 55-year-old father of two is now set to represent the United States in sailing at the Paralympics.
"It's an evolutionary process where you transition from one life to the other," Paul told CNN.
"I never gave up moving forward. You can define that as walking or being a contributing member of society. At 26 I chose the latter."