Jon Stewart was born in 1961. He has become an American Ninja Warrior icon, proving to millions that any obstacle can be overcome at any age. Also known as “The Rockman” because of his 30 years of climbing experience, Stewart loves teaching ninja warrior skills to kids and encouraging others on their path to fitness. Rockman doesn’t believe in being old but in living young. He is 56 now and says he’ll compete until he decides to pursue the next obstacle.