11/05/2012 08:45 am ET

Dream Big! Lessons Oprah Learned from Inspiring Achievers (VIDEO)

Do you have the courage to go after your most impossible dream? Oprah says if the road to what you want isn't difficult, then you aren't dreaming big enough. On "Oprah's Lifeclass," she shared what six of the biggest dreamers in the world taught her about living without limits.

Ted Turner says his father taught him to set his goals so high he couldn't achieve them in his lifetime. "I'm trying to help save the world and I don't anticipate achieving it completely, but I'd like to," he says.

Surfer Laird Hamilton says striving for more is second nature. "I have morphing goals. When I get near it, I change it," he says.

Pastor Joel Osteen says he never meant to take over his father's congregation. "See, we thought if we could just maintain what my parish had built that would be great," he says. "But I don't think that's God's dream. He wants every generation to build and go further."

Relationship expert Iyanla Vanzant says when you create a vision for your life, doors open. "If you don't have a vision, you're going to be stuck in what you know," she says.

When Academy and Grammy-Award winner Jennifer Hudson wanted to share her voice with the world, she says she just kept believing. "I know it's going to happen. I don't know when, I don't know where, I don't know how, but I'm just going to sing my way to it," she says.

And chef Paula Deen says anyone with a dream should just go for it. "There's no sin in failing," she says. "The sin is in never trying."