(CNN) - Meet Paul Alexander, one of the last people in the world still in an iron lung. 

The iron lung works to change air pressure and stimulate breathing. It's been his home, keeping him alive for 70 years.

In 1952, Paul contracted polio and became paralyzed from the neck down. He was 6 years old. 

A therapist promised Paul a dog if he could breathe on his own for three minutes. 

"I developed away to get air and breathing," Paul said. "I worked on it for a year before I could reach that three minutes, but I reached it."

Eventually Paul would be able to gulp or take in air for hours at a time, allowing him to leave the confined of the iron lung during the day and accomplish more than anyone thought was possible for him: college, law school and a 30-year career at a courtroom attorney.

Paul wrote his autobiography and he's working on a second book now. 

"But I've got some big dreams," he said. "I am not going kind to accept from anybody their limitations on my life. Not gonna do it. My life is incredible."