Neil deGrasse Tyson became passionate about astrophysics when he was a teenager. Best-selling science journalist. Mary Roach is well-known for her humor and curiosity as she explores the science of keeping human beings intact, sane and awake during the extreme circumstances of war.

This "Fix It" episode is about passion and is inspired by our many guests. They bring their wisdom, emotion and enthusiasm with them as they describe what turns them on about their work and expertise.

Obstetrician-gynocologist Rose Gowen, born and raised in Brownsville, Texas, speaks about her mission to get her small city with a large obesity problem to exercise more and eat better food. "Pretty much all of my father's side of our family has diabetes," she says.

Emily Esfahani Smith's passion for learning from strangers prompted her to write the book "The Power of Meaning: Crafting a Life That Matters." She talks about the roots of her discoveries.

Author, investment expert and asset manager Karen Firestone has spent her professional life studying financial risk. She explains why risk "applies to other aspects of life beyond investing."