You're only given a little spark of madness. You mustn't lose it.
Williams isn't celebrating recklessness or eccentricity for its own sake—he's identifying something more precise: the irreplaceable part of you that refuses to accept "that's just how things are." That spark is what makes a nurse stay late for a patient nobody else notices, or what drives someone to paint in a cramped apartment when everyone expects them to choose stability. The real danger isn't losing it to age or responsibility, but to the slow erosion of small compromises, where you stop trusting your instincts because you've listened to too many sensible voices. The word "spark"—not flame, not fire—suggests something fragile enough to snuff out accidentally, which is why tending it matters.