Philip K. Dick(1928-1982)

Though many of his works were adapted by Hollywood, Dick had long passed away when the royalties for his works started coming in. He had poorly managed his business affairs and as a result, didn't see many royalties from his novels and short stories. This left him living most of his life in relative poverty and squalor. He received a large payment for the rights to "Do Androids Dream of Sheep?", which helped him have financial freedom for the first time in his life. However, he died shortly after the release of "Blade Runner" and never got to enjoy the money from that adaptation or any of the other ones made after his death, which likely would have made him one of the highest paid writers in the world.

Reality is that which, when you stop believing in it, doesn't go away.