Sadly, a classic example are the works of Philip K. Dick.
When the 2nd remake of Total Recall appeared, I thought it time to read the original story, We Can Remember It For You Wholesale.
The later version of the movie had a different plot line than the first. I wondered, which was closer to Dick's story?
The answer: neither movie followed Dick's plot development. The only thing common between the 2 movies and the story was the gimmick of implanted memories.
What's annoying is that I would love to see a movie that developed the direction Dick's story took about the revelation of the implanted memories.
The short story would have made a good episode of Twilight Zone or Outer Limits. For a movie it could have expanded the twist revelation at the end of the story.
But the combined wisdom of the movie makers decided they knew how to write better than Dick.
Both films are basically vehicles for chase sequences, with little imaginative punch - the second film being the worst in that regard. At least the first Total Recall created a mildly interesting stew of imaginative elements for the ending.
I urge you to read Dick's original story (do not read the wikipedia entry, or any other summary). The ending left me with a wide grin as Dick popped his Jack-In-The-Box surprise.
The two Total Recall movies only confirm how poorly film makers write, throwing out the best part of an original work.
###