My favorite "remote debugging" of all time was the caller who complained about the key in her old Subaru wagon not working sometimes. After some back and forth

My favorite "remote debugging" of all time was the caller who complained about the key in her old Subaru wagon not working sometimes. After some back and forth, one of the brothers said, "wait, wait--I'll bet you have a huge set of keys, right?" "Well, yes." "So, on that model of Subaru, the weight of the whole key set will eventually wear down the lock and make it stick. I've seen that before." I can't imagine the leap of intuition required...