Colonel Sanders did not even BEGIN his chicken-selling business until he was 66 years old. I like that -- and he did so out of need: he had been running a service station and selling his fried chicken on the side for several years, when an interstate highway was completed that routed traffic away from his station and forced him to close. He used $105 from his first Social Security check to fund his new project, and began his KFC business out of his pickup, driving around and selling chicken that he was frying up in the back of the truck. Within a couple of years, he sold the franchise for $2 million and remained involved as company spokesman until his death at age 90.
William Shatner was a Shakespearean actor who had appeared several times on Broadway when he got the role of Captain Kirk on Star Trek. After its three-year run, he couldn't find work elsewhere - he'd been typecast as Kirk - and concurrently with the show ending, his wife divorced him. Soon, Shatner was living out of a camper-covered pickup truck, and finding gigs doing special appearances at kid's parties to make ends meet. He had to start over at age 44 - he kept on moving forward, and appeared in guest star slots in Columbo, and other tv shows, as well as on game shows, and got his second big break when he was 51, in the TV show TJ Hooker. He's gone on to write lots of science fiction books, win Emmy and Golden Globe awards for his role as Denny Crane on Boston Legal, achieve respect in horse circles for his thoroughbred ranches, and while his spoken-word album has been the source of lots of laughs, he's actually gained respect in jazz circles for his second album, which had lots of famous folk participating in it (Joe Jackson, Ben Folds).