A woman balancing on top of a stack of briefcases

Erin, a performance coach for corporate executives, is standing at the front of a conference room at the Virgin Hotel in downtown Nashville. At 5 feet tall, she's tiny, blond, and freakishly fit. She's also, perhaps, the peppiest person I've ever met — the kind of energizer bunny perfect for rallying a yet-to-be-caffeinated audience at 9 in the morning. So, like any good motivational speaker, she starts with a joke.

"I want to say: Drink the Kool-Aid," she announces. "But the people who drank the Kool-Aid died."