Dr. Leo Marvin is a successful therapist with a best-selling book out and a gig with a morning show scheduled. He is also veryarrogant.He takes on one appointment with a patient, Bob, who has been transferred from psychiatrist to psychiatrist. Bob has pantophobia — he's afraid of everything. Dr. Marvin encourages a first-name basis, as psychiatrists do, and recommends his book to Bob.Bob's hero-worship for Dr. Marvin begins immediately. Unfortunately for Bob, Dr. Marvin is going on a trip to his vacation house and does not want to bring work along with him. It's a family vacation for a seriously messed-up family. Unfortunately for Dr. Marvin, Bob is not going to give up that easily.Bob learns where Dr. Marvin will be staying and follows, bringing just his essentials and his goldfish. He has subtle encouragement from the locals, who disapprove of Dr. Marvin and are only too happy to let this lunatic interfere with his peaceful vacation.The fun begins when Bob and Dr. Marvin's family meet. Bob almost accidentally helps everyone with their problems — except Dr. Marvin, whom he is unwittingly driving over the edge...
All Psychology Is Freudian: To the point where Dr. Marvin named his son Sigmund and his daughter Anna (the name of one of Freud's daughters and the one to follow him into psychoanalysis).
Establishing Character Moment: When Leo prescribes that Bob read his book, he pretends to scan his bookshelves looking for a copy when there's obviously an entire shelf of them prominently placed. False modesty much?
The Fool: Bob. Without even trying, things just work out great for him all the time.
Insult Backfire: All of Leo's insults, threats and, eventually, murder attempts are like water off Bob's back, as Bob is convinced that it's all merely part of the therapy. Indeed, throughout the movie he has nothing less than the utmost respect for Leo.
It's All About Me: Dr. Marvin is this in regards to his patients. He's merely concerned with stroking his own ego over helping people. Over the course of the movie when he attempts to actually treat Bob, he gives him either vague, meaningless advice that could apply to anything, or gives him advice that really has no real ability to help him; such as telling him to simply "Take a vacation from [his] problems." When Bob first walks into his office, Marvin listens to his case with the most profoundly bored expression before just handing him a copy of his book and telling him that it will solve everything (making a note to bill him for said book later).
This point is driven home when he receives notice in the middle of the night of Bob's (faked, unbeknownst to him) suicide early in the film. His reaction is to nonchalantly say that they shouldn't let it spoil their family vacation and promptly goes back to sleep, his lack of concern making him look very insensitive.
Karma Houdini: Jackass or not, Leo doesn't deserve a lot of what Bob does to him. Bob's "punishment" is getting to marry Leo's sister. It does kind of help that Bob is well-meaning and often doesn't realise the trouble he's causing for Leo until it's too late.
Laser-Guided Karma: Given that Leo is a Dr. Jerk and that Bob doesn't mean to inflict his neuroses on other people (if he was smart enough to understand what he's doing to Leo, he'd be horrified), the whole movie is just the universe evening things out for Bob by letting Leo's previous behavior and treatment towards his family and other people come back to bite him in the ass. Literally, as things get better for Bob they get worse for Leo.
Let The Past Burn: Dr. Leo Marvin's lakeside vacation house in New Hampshire is a symbol of his financial success at the cost of strained relationships with just about everyone. (His son calls the trip there "another vacation that isn't a vacation", and his neighbors—the Gutmans—hate Dr. Marvin because they were saving up to buy that house.) At the end, Dr. Marvin tries to kill Bob with explosives, but ends up burning down the house instead. This is the straw that finally breaks Dr. Marvin, and in the next scene he's more or less catatonic. And in the next scene, Bob unintentionally shocks Dr. Marvin back into full consciousness. Whether or not Dr. Marvin learned anything from the ordeal is an open question.
Loony Fan: Bob was recommended by his last therapist to Dr. Marvin. Bob takes a liking to Leo to the latter's chagrin.
Minor Flaw, Major Breakup: Bob divorced his wife because she loved Neil Diamond. Perhaps the only real bit of psychological help Leo gives him is suggesting he actually divorced her to avoid rejection.
Only Sane Man: Leo is the only one to notice Bob's obvious insanity, instability, and inappropriateness. All the supposedly normal people side with Bob against him. Although it kind of helps that Bob, while clearly not very well adjusted, is ultimately pleasant, friendly, well-meaning and likable, while Leo is a cold, arrogant, and thoughtless prick even before Bob enters his life.
This is gradually inverted as the movie goes on, with Leo becoming more unstable as Bob begins to get better.
Parental Neglect: The fact that Leo's wife and kids actually get along better with the neurotic and phobic Bob, who had driven previous psychiatrists insane, should tell you something about what a horrible husband and father Leo is.
Placebo Effect: Bob taking "baby steps" actually does help distract him from his fears a bit, which is part of what makes him believe that Leo is a great therapist.
The Red Stapler: Bob's turquoise and yellow "Don't Hassle Me I'm Local" T Shirt
Sanity Slippage: Leo suffers this the more Bob gets involved with his family. Conversely, Bob experiences the inverse the more he gets involved with Leo and his family, gradually going from a neurotic mess to a well-adjusted man.
Sink or Swim Mentor: Leo unwittingly and unwillingly becomes this for Bob — the more desperate his attempts to get rid of Bob become, the more Bob assumes that this is all part of the therapy, and the more Bob ends up being helped by it, to the point Leo unwittingly helps Bob become a healthy and functioning person.
Small Name, Big Ego: Leo is incredibly vain about his modest success as an author and in getting a television interview.
Strapped to a Bomb: In the climax, Dr. Marvin snaps and tries to kill Bob by tying him up in the woods and hanging 20 pounds of black powder around Bob's neck. Leo jokingly refers to this as "Death therapy, a guaranteed cure!"; Bob is completely oblivious to how much Leo hates him, so he immediately accepts that this really is some kind of therapy. Bob effortlessly unties himself, but assumes the still-ticking bomb is a prop and takes it with him back to Leo's house.
Stuff Blowing Up: What "Death Therapy" was meant to be. Bob brought the explosives into the house after he got out of the bindings Leo had set tied him with.