George Carlin, the gnarly American comedian most famous for his bit on the seven words you can't say on radio and television, used to do a routine back in the late 70's during which he reflected on the idea that urinals are 50% universal. It is true, because there are only two types of people in this world, those who would/could use a urinal, and those who wouldn't. Hearing that routine back in those days was both funny and enlightening. Here was this thing that was so common to 50% of the population, and yet to the other 50% it was an unknown, a mystery. I used to have this impulse to photograph a urinal (which I did) and frame it and hang it on the wall (which I didn't)--solely for the purpose of enlightening the other 50% of the population.
Photographers know all about the common and the uncommon, making the common seem fresh and different, and bringing the uncommon home, so the viewer can identify with it. Whether it be the 30th pepper, a Sambos Restaurant parking lot, or the atrocities of war.