Other Person #1: someone who's seen it once, and liked it but, like most of us, didn't quite "get" it that first time.
Other Person #2: someone who's never going to see it at all. I feel confident predicting this. It's just not her thing.
Me and OP1 spent quite a while on Saturday trying to explain the film to OP2. AND LOVED CONFUSING THE HELL OUT OF OP2. OP2, to her credit, went along gamely with our geeking out and laughing throughout the discussion and its digressions. (OP1 loved that Raymond Chandler, whose work was an inspiration for the film, once was asked who had killed a chauffeur in one of his novels, because the book never answered that question, and said "Oh, him. I forgot all about him. What happened to him? Hell if I know!")
I was also able to use the way I summed up the film back in 1998, which was "[It] doesn’t make sense, but it avoids making sense in a way that makes sense." (I didn't add my "(Did that make sense?)" I didn't want to confuse OP2 TOO badly.)