So what else have these folks done that also had them thinking outside the box?
Melissa Gilbert says she sets goals for herself on milestone birthdays.
"When I turned 40 I learned how to surf and by the time I'm 50 I want a pilot's license and learn how to fly," she said.
For Gladys Knight, it was acting.
"I was totally out of my comfort zone there," she said. "I'd done a lot, but not at the level that I'd like to be as an actress."
Donald Driver says having kids was something that took him out of that zone, but he was glad he did it.
"For me, I never wanted to have kids before, and then to have three beautiful kids now, it's truly something special," he said.
Katherine Jenkins said for her it was performing on the other side of the world.
"I've been going out to do concerts in places like Iraq and Afghanistan and that's a completely different thing," she said. "You kind of got to go, there's no glamour to it, you just got to go out there and do the best show as you can and I think that was out of my comfort zone. But I'm so glad I did it, one of my best experiences ever."
Another contestant will be cut from the lineup during the results show at 9 p.m. Tuesday on ABC7.