Going up to collect the Oscar for the Best Documentary Short “One Survivor Remembers,” director Kary Antholis thanks the short’s subject, the Holocaust survivor Gerda Weissman Klein. When Klein herself steps up to the microphone, however, you suddenly feel a much more profound sense of gratitude emanating from the stage. “Thank you for honoring their memory,” she said, referring to the family, friends and millions of innocents who did not survive. “Each of you who know the joy of freedom, [you] are winners.” This is not a victory lap for Klein. It is a reminder to never forget.