Despite how it's often portrayed in blogs, scientific articles, or corporate test planning, fuzz testing isn't a magic bug printer; just saying "we fuzz our code" says nothing about how effectively it was tested. Yet, how fuzzers and programs interact is deeply mythologised and poorly misunderstood, even by seasoned professionals. This talk analyses a number of recent works and case studies that reveal the relationship between fuzzers, their inputs, and programs to explain how fuzzers work.