An old A&P in Wichita told me to stop reusing cotter pins, and my last 3 annuals have been way smoother
I used to just bend them back straight and run them again to save a trip to the parts bin, but he said it once and it stuck: "They're 30 cents, do you want to explain a jammed nut to the FAA?" Curious if anyone else had a habits changed by one comment from a graybeard.