In both the book and movie versions of Flowers for Algernon, Charlie didn't understand the concept of the inkblot, or Rorschach, test. In the end, he started to understand what the test was about.
the bakery (difference)
Oops, he pulled a Charlie Gordon!
In the book and the movie, Charlie beat Algernon in the maze race, and he was very excited about it. It took him a while to figure out the maze. Him and the test guy celebrated after he beat Algernon.
the conference (difference)
He didn't tell me what would actually happen to me!
At the end of the book and movie, Charlie asked Miss Kinnian to remember to put flowers on Algernon's grave. Algernon was very important to Charlie. When he died, Charlie was really sad, and left.
In the book, Charlie works at Mr. Donnegan's box factory. In the movie, he works at Mr. Donner's bakery. But the guys that work with Charlie are still rude to him.
In the book, Charlie didn't go to any conference. In the movie, he went to a big conference ad caused a huge scene by releasing rats into the crowd. He was angry because he wasn't like the old Charlie.
In the book, Charlie never brought Algernon to a bar with him. In the movie, Charlie brought him to a bar, left him on the counter when he was dancing, and he drank alcohol. Charlie was starting to act like the old Charlie Gordon.