Michael Maren talks about writing and directing “A Short History of Decay,” along with Bryan Greenberg and Harris Yulin, who star in the film. It is based on Maren's personal family story. Greenberg plays Nathan Fisher, a 30-something Brooklyn writer whose career is stalled. When his father falls, he plans a quick visit to his parents that turns into an extended stay during which he discovers that his aging parents are actually in much better control of their lives than he is. "A Short History of Decay" opens May 16 at the Village East Cinema.