There is no better insight into the idiosyncrasies of human nature than our deep and enduring love for signage. Both the signs themselves and the fact that they need to be there in the first place show us that as a species, perhaps we're not as intelligent as we like to make ourselves out to be.
Behind every (not so) meticulously typed or scrawled sign, there is a story. Sometimes, it's just a case of somebody being over cautious. Others, some weirdo has really outdone themselves in a way that's got someone else firing up Microsoft Word with a fury that could slay a thousand people.
Whatever their reason for being, the thing that unifies all signs is that they have a sense of purpose. They give us a gentle nudge in the right direction of doing things, or at least have us stop for a moment and scratch our heads at what exactly they're supposed to mean. Signage is one of the few great unifiers of our age, and for that, we should be thankful.