While working for an organization that delivers lunches to elderly shut-ins, I often take my four-year-old daughter on my afternoon rounds.
She was unfailingly intrigued by the various appliances of old age, particularly the canes, walkers and wheelchairs.
One day I found her staring at a pair of false teeth soaking in a glass. As I braced myself for the inevitable barrage of questions, she merely turned and whispered, "The tooth fairy will never believe this!"