When somebody is trying to sell you a used car and the brake pedal is excessively worn, that's a possible danger sign ... the vehicle may have been driven a lot more harshly stop-and-go than the average. (And if the brake pedal is brand-new, ask yourself why it was changed so recently.)
Wear-indicators exist elsewhere too. The soles of a runner's shoes are a superb diagnostic tool in identifying stride problems. Blisters on the feet are similarly significant. The Koebner Phenomenon --- where minor skin abrasion triggers a local flare-up of psoriasis or other dermatitis --- troubled me some years ago until I understood it and learned to learn from it. And in the mass transport world, modern automobile tires have tread-wear markers that give warning when the rubber is getting dangerously thin.
In another realm, recently I noticed that the buttons on my car radio are quite worn --- and I've gotta admit that they're telling me the truth about myself. I'm impatient. When there's a commercial break or when a song comes along that doesn't grab me right off, typically I'll click to another station, then another and another --- seeking not just good enough but zow! So I flit along and rarely listen to anything that doesn't appeal to me from the start. And because I've wandered off I frequently don't get to hear the beginning of something I would have enjoyed.
I'm working on this, but for me it's a tough habit to change. Sure, I avoid getting stuck with a dull song for a few minutes --- but the net result is to miss a lot more that would have turned out to be worthwhile and pleasurable.
The same hurrisome behavior applies in other areas of my life. I blitz through newspapers and magazines, rather than settle down to read longer articles or books. Web browsing for me is the same, but on steroids. Maybe it's an archetypal "male" tactic? That's no excuse!
And on my computer keyboard the letters "A" and "I" are almost illegible, the paint mostly scraped off the tops of those two keys by my frenzied typing. Wonder what that means?