"Can sunshine make you sneeze?"
Goldberg says this is one of his favorite questions—mostly because he assumed it was too ridiculous to be true. While writing Why Do Men Have Nipples?, Goldberg and Leyner pored over medical textbooks and studies to find out that some people have a strange reaction to blazing sunlight that brings on an uncontrollable sneezing fit. This is due to something called the photic sneeze reflex—also known as autosomal dominant compelling helio-ophthalmic outburst, or ACHOO. A 2005 study of six Spanish families showed that there are usually two to three "achoo"s per episode of ACHOO. This reflex is relatively under-studied and not completely understood, says Goldberg, but it is thought to have something to do with an accidental crossing of nerve signals.