"I pay too. They also pay who meet in hotel rooms."
Marion's use of the word "pay" has two meanings here. Sam has just been complaining about paying his alimony and chipping away at his father's debts. While he cannot get married for financial reasons, Marion is reminding him that, as a woman, she is paying for their affair with her reputation. Because of society's prescribed gender roles, Sam has the power in their relationship; he gets to decide when to legitimize it. This imbalance, then, is what ultimately leads Marion to theft - marriage is much more crucial to her happiness than it is to Sam's. This quote also foreshadows Marion's death, which occurs in a hotel room - she pays for her crime with her life.
"Aren't you going to take the pills? They'll knock that headache out."
"Can't buy off unhappiness with pills."
This quote foreshadows Marion's theft. Again, Marion uses a word ("buy") that refers to the power of money. Cassidy has said that he buys off his unhappiness with money, an option that is not open to a woman like Caroline, who uses pills to tolerate her marriage and her overbearing mother. Once Marion has money, then, she will have power; Cassidy's $40,000 will allow her to transcend society's restrictions on her gender and allow her to get what she wants.
"But there's no sense dwelling on our losses. We just keep on lighting the lights and following the formalities."
First of all, Norman's use of the pronoun "we" foreshadows the revelation that there is someone besides him at the Bates Motel. It also sets up the idea of Norman trying to function normally despite the secrets that have torn him apart psychologically. Just as he maintains the illusion that the Bates Motel is a functioning business, he also pretends that his mother is still alive and that her betrayal and death never occurred.
"You know what I think? I think that we're all in our private traps, clamped in them, and none of us can ever get out. We scratch and claw, but only at the air, only at each other, and for all of it, we never budge an inch."
Norman uses bird-related language here ("we scratch and claw...") to describe his difficult situation. At this point, we (and Marion) believe that Norman is referring to being trapped at the Bates Motel, caring for his ailing mother, but it later becomes clear that Norman could also be describing what it feels like to be trapped in a state of psychosis. Unlike Norman, though, Marion can get out of her trap, which she realizes during this very conversation. Despite the fact that Marion is never able to return to Phoenix and redeem herself, both she and Norman end up free from their traps, in a twisted way. Marion never has to confront the consequences of her theft because Norman kills her, and Norman never has to deal with his murders because his "mother" essentially kills him and takes his place.
"Mother! Oh, god - Mother! Blood! Blood!"
When Dr. Richman describes Norman's condition at the end of Psycho, he says that Norman does not remember any of the crimes that "his mother" committed. In this moment, right after the crime, we hear Norman transitioning from his "mother" personality back into Norman Bates. Hitchcock had Anthony Perkins say this line in a high-pitched voice, which makes Norman sound childlike. At this point in the film, it appears as though Norman is a selfless man who is saddled with the burden of caring for his elderly mother. However, the truth is that Norman has never learned how to confront his adult sexuality; he is more comfortable in the role of a dutiful young son, which is what he reverts to here.
"No! I will not hide in the fruit cellar! You think I'm fruity, huh? I'm staying right here. This is my room and no one will drag me out of it - least of all my big, bold son."
At this point in the film, it seems as though Norman is a sympathetic bystander; he has just been trying to maintain peace in the Bates home and the Bates Motel. However, in trying to be kind to Marion, Norman ignited his mother's murderous passion. Now, he is trying to save his invalid mother from being sent off to one of "those" places because of his duty as a son. It will soon come out that Norman has been trying to maintain equilibrium - but only in his own mind. Both the act of killing Marion and then "protecting" his mother are all part of the delusion that Mrs. Bates is still alive. Therefore, her protest takes on a double meaning. She wants to stay "right here," both in her bedroom and in Norman's consciousness, no matter how hard he tries to fight her off.
"You're alone here, aren't you? It'd drive me crazy."
"I think that would be a rather extreme reaction, don't you?"
This line is an example of Hitchcock's dark, macabre sense of humor; the audience is not yet prepared for how extreme Norman's craziness truly is. In this conversation with Sam, Norman is trying desperately to cling onto the reality he has carefully constructed for himself. This statement, then, is his attempt to deflect Sam's suspicion. The exchange also solidifies the parallels between Norman and Marion because it recalls when Norman said to Marion, "we all go a little mad sometimes," and Marion replied, "sometimes just once is enough." Norman knows that Sam does not understand madness the way that Marion did; both Sam and Marion act out of passion, which separates them from the practical-minded characters like Sam, Lila, and Arbogast.
Meanwhile, Sam does not see the irony of accusing Norman of going "crazy" and stealing the money from Marion, when, in reality, Sam is the one who drove Marion to commit said "crazy" crime in the first place.
"This place happens to be my only world. I grew up in that house up there. I had a very happy childhood. My mother and I were more than happy."
When Arbogast arrives at the Bates Motel, he tells Norman that it looks to be "hiding from the world." This is a prophetic statement on Arbogast's part because Norman is hiding from the world. The Bates Motel is the only place where Norman's idyllic childhood with his mother is still a reality. It is only in the Bates house where Norman can act out his delusion without arousing public suspicion.
"A psychiatrist doesn't lay the groundwork. He merely tries to explain it."
Norman's fantasy world enters the practical world in the final scene of Psycho, and Dr. Richman serves as a translator. Just as Norman's crimes are passionate, not practical (i.e. there is no concrete motivation, like money), Dr. Richman is not trying to judge the legality of Norman's actions. He is simply presenting the facts as he knows them; he is not trying to influence the outcome of Norman's capture. Similarly, Norman never cared about the state of his business or his finances; he just wanted to maintain his delusion. Neither Norman nor his "mother" are hardly thinking about a plea bargain at this point - such legal formalities do not apply to the world of desire in which they exist.
"They know I can't even move a finger. And I won't. I'll just sit here and be quiet, just in case they do... suspect me. They're probably watching me - well, let them. Let them see what kind of a person I am. I'm not even going to swat that fly. I hope they are watching. They'll see. They'll see and they'll know and they'll say, 'why she wouldn't even harm a fly.'"
"Mrs. Bates"'s final monologue concludes the thematic arc of voyeurism in Psycho. She believes that she is putting on an innocent act for the policemen, who will never suspect an innocent old woman of slaughtering so many people when she can't even hurt a fly. Similarly, Marion does her very best to maintain an innocent image while running off with Mr. Cassidy's $40,000. While both these characters might appear one way to the world around them - Marion, the nice girl who just wants to have an honest relationship, and Norman, the dutiful son who wants to protect his mother - Hitchcock makes us privy to their inner monologues, which reveal their true motivations.
