Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title
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Question: Saw this 1959 Hitchcock's masterpiece Rear Window last night. One of the great classics! Enjoyed it!  I just didn't get one thing. Why didn't Lisa (Grace Kelly) tell the complete plot and truth about Thorwald when the police arrived at his home? Why did she get herself arrested and made the things more tense? Thorwald could have ran away from that place (but thank god it didn't happen)! :-/

Answer: Why didn't Lisa tell the truth about Thorwald to the police?


Question: I have watched many movies such as Sixth Sense, where there is a major twist that if known prior to watching the movie can potentially spoil the enjoyment of viewing. I tend not to watch this type of movies again, or certainly no more than once, and wondered if this is a common reaction.  Is there any evidence that would suggest that comparatively, this type of films, whilst they may do well at cinema, have relatively poor post-cinema sales (I am thinking of the ratio between box-office and DVD/BluRay sales). So, for any budding directors, is this the type of movie to shy away from?

Answer: Is there any evidence of "Big Twist" movies having poor post-cinema sales?


Question: In Se7en, John Doe is tracked to his residence by Detectives Mills and Somerset due to activity on his library card:    "Divine Comedy", "History of Catholicism", A book called "Murderers  and Madmen", "Modern Homicide Investigation", "In Cold Blood", "Of  Human Bondage". The Marquis de Sade. Works of Saint Thomas Aquinas.  There. He wrote about the seven deadly sins.   These are the books that John Doe had checked out. John Doe was shown to be extremely knowledgeable in the Seven Deadly sins. He obviously had been studying them for quite some time to the point of obsession.  Also, we see that John Doe's apartment is stocked with several books.    I understand that the notebooks to the left of Somerset are John Doe's personal writings. However, there are several books shown in his apartment.  The police officer even states how well educated and wealthy he is.    All we know about him is that he's independently wealthy, well  educated and totally insane.  Is it ever explained why John Doe would need to check out books from a public library on a subject that he is obviously already well versed in?

Answer:
Why did John Doe need to check out books at a public library?