The Diagnostic and Statistical Manual of Mental Disorders, the go-to psychiatric illness index, once characterized delusions into two categories: the bizarre and nonbizarre, which were respectively described as impossible and possible but false. "'I am dead,' is bizarre," Marantz writes."'Millions of strangers are obsessed with me' is nonbizarre (and, for Ryan Gosling, nondelusional)." But the DSM-5, the latest version of the book, had to walk back that distinction. As it should have: In a world where the government really does have the capability to broadly and furtively spy on its citizens, it's suddenly delusional to not think Big Brother is watching. In a world where a tweet can almost instantly be read by millions, becoming famous seems more and more plausible.