I am trying t find the name of a movie that is about a very successful arrogant doctor that has his life totally changed when he goes out to buy a pack of cigarettes and is shot during a robbery. He sustains brain injury that changes his life for the better. Help!

Regarding Henry (1991)
Starring Harrison Ford, Annette Bening
IMDb synopsis:
Henry Turner is a despicable and ruthless trial lawyer whose life is turned upside down when he is shot in the head during a robbery. He survives the injury with significant brain damage and must re-learn how to speak, walk, and function normally. He has also lost most of the memory of his personal life, and must adjust to life with the family that he does not remember. To the surprise of his wife and daughter, Henry becomes a loving and affectionate man.

http://www.imdb.com/title/tt0102768/

As I recall, the young man who shoots him is played by John Leguizamo, early in his career.