Walter Sparrow becomes obsessed with a novel that he believes was written about him, as more and more similarities between himself and his literary alter ego seem to arise.
 
There are 23 letters in the sentence - This film is worth your time
 
FUN FACT:  Jim Carrey claims to have been obsessed with The Number 23 long before being a part of the movie. His production company is called JC 23 Entertainment. It was coincidence that his father was an accountant and he played the saxophone, like his character in the movie.