What “Maybe Happy Ending” asks, even in its ambivalent title, is whether that’s a good thing, for them and for us, their mirror images. When Oliver fully realizes that Claire’s “shelf life” will end before his, he asks in real pain, “How can people do this?” — meaning survive the death of others. If the start of love is the start of loss, is it perhaps better to erase one’s memories (which these Helperbots can do because they have their own passwords) or even to avoid the journey altogether? A good question for robots and, as posed by this astonishing musical, maybe the most deeply human one of all.