the worst is ... being out on a ride, flying down the road, hearing something now well behind you hit the pavement and roll like a large coin, thinking little of it, most assuredly not stopping and searching feebly for what's most likely a metallic piece of junk ... then to arrive home and notice a rare pedal dust cap missing from your original pedals.

Been there and pedal cap still missing. Sad event.

Yup. Dust caps are not cool.