[kennyc]

Flowers for Algernon by Daniel Keyes is a famous (science fiction) short story.

from wikipedia (contains spoilers in case you haven't read the story):

Spoiler:

In 1958, Keyes was approached by Galaxy Science Fiction magazine to write a story, at which point the different elements of Flowers for Algernon fell into place.[9] On submitting the finished story to Galaxy, however, the editor suggested changing the ending so that Charlie retained his intelligence, married Alice, and lived happily ever after.[9][11] Keyes refused to make the change and sold the story to The Magazine of Fantasy and Science Fiction instead.[9]

Keyes worked on the expanded novel between 1962 and 1965[12] and first tried to sell it to Doubleday, but they also wanted to change the ending. Again, Keyes refused and gave Doubleday back their advance.[11] Five different publishers rejected the story over the course of a year[11] until it was taken on and published by Harcourt in 1966.

http://en.wikipedia.org/wiki/Flowers_for_Algernon