NATICK, Mass. -- Don't tell Jothy Rosenberg that he can't do something. He'll just prove you wrong.

Rosenberg has been exhibiting a "can do" attitude since 1973, when as a high school sophomore, he lost his right leg to a rare form of bone cancer. He came to Natick Soldier Systems Center Oct. 24 to tell his story as part of NSSC's Disability Employment Awareness Month observance.

"I was a teenager," Rosenberg recalled. "I had to learn to overcome a lot of adversity."

More was on its way: Three years later, the cancer spread, Rosenberg had to have a lung removed, and he was told that his chances of survival weren't good.

"What they said at the time was when this has happened to people in the past, no one has ever survived," Rosenberg said. "That was true, but that's because chemotherapy hadn't been invented in 1973, and by 1976 it was out."

Rosenberg underwent chemotherapy, and here he stood decades later on one leg and a $60,000 computerized prosthesis -- a married man of 34 years with three children, a grandson, two dogs and great professional accomplishments. Through it all, he kept a well-honed sense of humor.

"You should see me dance in this thing," Rosenberg said of his prosthesis. "I just got back from my son's wedding, and I was amazing."

Once Rosenberg had survived cancer, the rest of his life opened up to him. He began by skiing 100 days straight, finishing college and adding his doctorate. He went on to teach at Duke University and to start eight technology companies. Rosenberg is currently technical director and principal investigator (computer science research) at BAE Systems.

Along the way, Rosenberg became an author, speaker and host of the reality TV show "Who Says I Can't." The road back, he said, began with sports.

"I kind of became addicted to sports as my way to build back up," Rosenberg said. "I think we all have limitations. I think we all need something that we can excel at if we work really hard at it, and that confidence carries over to everything.

"There's got to be something … that will help you feel better and better about yourself, and you're going to be better (at) your job."

Rosenberg became an endurance swimmer and cyclist and has done a number of other sports. He jumps rope on one leg better than most people can on two.

"The fear of death began to slowly subside," Rosenberg said. "It made me kind of a risk-taker."

His experiences taught Rosenberg about people and their reactions to adversity.

"When something really bad happens to you … the first casualty is your self-confidence, which is how you feel about your abilities," Rosenberg said. "But that quickly degrades your self-esteem, which is how you feel about yourself. Humans cannot live a healthy life without good self-esteem."

Rosenberg said that everyone faces limitations at some point in his or her life.

"We're all capable of a lot more than we realize, especially when we're challenged," said Rosenberg, "and those people who are amazing are all around you."