How do you work through your greatest fears so you can make it to the top of the mountain (and not let your failures define you)? Melissa Biggs Bradley talks with mountaineer Alison Levine about the incredible places she’s been, completing the adventurer’s grand slam: climbing the seven summits and skiing to both the North and South Poles; plus, life lessons learned along the way—and why going backward doesn’t mean you’re not making progress.