Milos Forman won Oscars for directing ''One Flew Over the Cuckoo's Nest'' and ''Amadeus''; his other films include ''Hair,'' ''Ragtime,'' ''Valmont,'' and (before he fled Communist Czechoslovakia) ''The Firemen's Ball'' and ''Loves of a Blonde.'' But the brutality of his childhood was no movie: Nazis murdered his parents and officially labeled him ''a child of the enemies of the Third Reich.'' In Turnaround, Forman writes with sharp documentary focus about those horrifying years, then mercifully shifts to a more engaging style to talk about making his films, even avoiding the usual technical chatter and interminable aestheticizing of many filmmakers. Some sections -- such as his portrait of James Cagney, whom he directed in ''Ragtime'' -- are a privilege to read, and some are just plain fun: He admits he blew a chance to cast the young Madonna in ''Hair,'' and he never fired anyone from a film except the brilliant cinematographer Haskell Wexler. You'll laugh out loud at Forman's encounter with Bruce Springsteen. Good directors are good storytellers, and this storyteller is a good autobiographer.