Rain Man is based on a premise so absurd that it undermines all the sentimental good feeling we are supposed to experience while watching it.  Charlie Babbitt (Tom Cruise), who is on the verge of bankruptcy, finds out that his father, from whom he has been estranged for many years, has died.  He goes back home in the expectation of inheriting his father’s estate, inasmuch as he is the only living relative, at least so he thinks.  But he finds out that aside from an old car and some roses, the entire estate, worth $3,000,000, has been put in trust for someone else.  That someone else turns out to be an autistic older brother he never knew he had (he never finds out why no one told him about this older brother, Raymond (Dustin Hoffman), and neither do we).

Charlie decides he is entitled to half the estate.  So far, so good.  Up to this point, the movie is more or less within the realm of what might actually happen in the real world.  In said real world, Charlie would have hired a lawyer to contest the will, and then he could have gone about his business while waiting for results.  I once had a cousin who left all her money to her lover.  I figured that was the end of it, cut and dried.  But a lawyer thought otherwise.  I signed an agreement with him, and two years later he sent me a check for $22,000.  Now, if a mere cousin can break a will, I figure one of the sons of the deceased has a really good chance of doing so.

Instead of just hiring a lawyer, however, Charlie kidnaps Raymond from the institution where he has spent most of his life.  Then, he calls the head of the institution and demands $1,500,000 in ransom to get Raymond back.  That would be all right if we were supposed to think Charlie is a criminal, but we are not.  We are supposed to ignore the fact that in the real world, Charlie would end up in prison.  Instead, we are supposed to believe that he is going to show up in court with Raymond by his side, saying, “I have him now, so give me the money!” as if that is going to strengthen his case.

In true Hollywood fashion, we get the best of both possible worlds.  Charlie comes to care for Raymond, forgoes his claim on the estate, sends Raymond back to the institution where he belongs, and promises to visit him regularly.  But, thanks to some card counting on the part of Raymond earlier in the movie, he and Charlie won $85,000 playing blackjack, just enough money to keep Charlie from being forced into bankruptcy.  But it is a little hard to enjoy this happy ending after spending half the movie suffering through that ridiculous kidnapping plot.