Men and Movies

Why do men think it is acceptable to start watching a movie when it is half over?? For example, in my house the two men decided to start watching a certain war movie this weekend. Mr. Loaf commented that he enjoyed the opening scenes, so we watched the first 20 minutes of the movie. Then we decided to watch a show about Killer Ice (put hands above head and start screaming as you run in circles). A hour later, we resumed watching the war movie which had 45 minutes left. I questioned the point of watching something that was half over and I was scoffed at for not getting it.