Here at the height of summer, when blockbusters (and would-be blockbusters) are hurtling through space like asteroids, I’m seeking stardust: something subtle, incidental, tangential. “Memorizu”—which premiered at Tribeca earlier this month—fits the bill, for anyone in the mood for a modest, haiku-like piece of film. The theme wastes no time (and no words) announcing itself: the opening shot is a woman on a ferry, looking out a wide window to the sea.