This is the diary kept by one of Sweden's young filmmakers-- My Sister, My Love, 491, The Mistress--during the impromptu creation of I Was Curious which is currently battling it out in the censorship courts. If you are curious about what it feels like to direct and/or star in an intimate sexual close-up, then this book should prove fairly gratifying. After breaking down the initial ""shyness barrier"" (in rehearsal) between Lena Nyman and leading man Borje, Mr. Sjoman finds himself ""faced with the great Swedish film bed in the great Swedish film studio (when) everyone concerned seems to lose all power of imagination."" This temporary barrier is also overcome and the filming moves on from locale to locale with the hero and heroine assuming more and more heroic positions. In between time, Director Sjoman assimilates and conveys his thoughts on the psychological network of response between himself and the actors; battles with ideas for scenes (including socio-political possibilities) and recalls cordial moments with Ingmar Bergman and dreams where he has bested this master. That remains to be seen. And it also is problematical whether the film I Was Curious will provoke an inquisitive audience for this book.