On Sunday, Oprah Winfrey revealed that she and TED speaker Brené Brown are “soul mates.”

Brené Brown: The power of vulnerability As the pair sat down for an in-depth discussion on Super Soul Sunday — part one of which aired last Sunday, with part two to air next Sunday — they excitedly talked about many of the concepts which Brown raised in her classic TED Talk, “The power of vulnerability.” One interesting moment came when Brown shared a counterintuitive thought on what scares us the most.

“As someone who studies shame and scarcity and fear, if you asked me, ‘What is the most terrifying, difficult emotion we experience as humans?,’ I would say joy,” says Brown. “When we lose our tolerance for vulnerability, joy becomes foreboding. Brené Brown: Listening to shame So what we do in moments of joyfulness is we try to beat vulnerability to the punch … We try to dress-rehearse tragedy.”

In fact, says Brown during the first part of this intervie,  fear seems to be an ever-present part of our experience.

“I think there’s a thin film of terror wrapped around us,” says Brown. “If it’s not, ‘I’m not safe enough’ or ‘I’m not secure enough,’ it’s ‘I’m not liked enough,’ ‘I’m not promoted enough,’ ‘I’m not loved enough’ … at the very bottom, ‘I’m not good enough.’”

Watch part one of Brown’s “Super Soul Sunday” appearance here »

And stay tuned to the Oprah Winfrey Network this Sunday, March 24, at 11am (EST) to see part two.