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.