Good - even amazing - theater can keep Washington patrons in their seats beyond the normal 10 p.m. rush to the door as proven by the current offering at Shakespeare Theatre Company's presentation of Eugene O'Neill's 'Strange Interlude.' It was Michael Kahn's stated gift to himself to tackle what was originally a nine act play - first shown in 1928 - and get permission to edit it down to three and a half hours. "For me it is a search for happiness," MK said in extensive remarks at a dinner preceding the April 2nd formal opening. "O'Neill explored theater the way Shakespeare did,' influenced by Freud, Jung and Joyce. Characters speak to one another and then in a masterly directorial way say aloud what is in their mind. 'You get to know characters inside and outside; the texture of the play is thought...' Guess what? Program notes say that O'Neill was undergoing psychoanalysis and reading Joyce's Ulysses during the writing of the play. Never underestimate the power of the unconscious and, for readers interested in understanding the psychodynamics of the creative mind (and biology's input), order up Eric Kandel's new book, 'The Age of Insight.'