Fromm isn't simply saying that creativity means taking risks—he's identifying a peculiar paradox: certainties feel like safety, but they're actually creative prisons. We cling to what we already know works, what's been proven, what won't embarrass us, and in doing so we foreclose the very uncertainty that birthed every original idea. A musician who masters classical technique must eventually stop trusting that technique if she wants to compose something no one has heard before; the certainty becomes a cage. The courage he describes isn't bravery in the face of failure—it's the harder work of voluntarily releasing the comfortable ground beneath your feet.