“You’ll never know what a Displaced Person thinks,” interjects Jonas Mekas in Lost, Lost, Lost, a patchwork of footage shot between 1949 (the year Mekas arrived in New York as a D.P.) and 1963, and edited years later into short, discontinuous sequences, like so many entries in a diary, so many bits and pieces of a life in exile. From this and other “diary films” that he has assembled in the same, painstaking way since the late ’60s, Mekas has now begun to extract selected images in the form of photograms. These “fragments of memory,” as he has called them, are enlarged from the films like prints