In the story Flowers for Algernon, in what ways are Charlie and Algernon similar and different?

Charlie is a thirty-two-year-old intellectually disabled adult with an IQ of sixty-eight who works at Donner's Bakery and attends Beekman College Center for Retarded Adults before undergoing experimental neurosurgery to significantly increase his intelligence. Algernon is the mouse that undergoes the same surgery and becomes extremely intelligent. Both Charlie Gordon and Algernon experience a significant increase in their intelligence following the surgery and impress Professor Nemur and the scientific community. After the surgery, they are both able to complete tasks that were previously considered much too difficult for them to accomplish. Both Charlie and Algernon are viewed as simple test subjects by Professor Nemur and contribute to the scientist's experimental research. Algernon's erratic behavior and health mimic and foreshadow Charlie's dramatic decline. They also suffer as a result of the surgery, and Algernon ends up dying before Charlie regresses back to his former intellectually disabled state.
Being that Charlie is a human and the protagonist of the story, his emotions, feelings, and actions take center stage and are significantly more complex than Algernon's. Despite Charlie's increased intelligence, he suffers severe emotional trauma as he reflects on his difficult childhood and adolescence. Charlie also develops feelings for Alice Kinnian and Fay and has brief relationships with both women. Charlie also gets into a heated argument with Doctor Nemur, and his increased intelligence significantly impacts his personality. Before Charlie experiences a sharp mental decline, he works feverishly to contribute to Nemur's body of work regarding neurosurgery to increase human intelligence.

At the beginning of Flowers for Algernon by Daniel Keyes, Charlie Gordon is a 32-year-old man with a very low IQ. He has a simple menial job and attends Beekman College Center for Retarded Adults to try to learn how to read and write. Algernon is a mouse.
These characters are similar in that they become subjects in scientific experiments that are designed to increase their intelligence. In both cases, these experiments are successful. Charlie and Algernon become much more intelligent than they used to be. Ultimately, the experiments end in failure because Charlie and Algernon both lose the intelligence that they gained through the surgery and revert to the way that they were before.
The difference between Charlie and Algernon lies in Charlie's human understanding of the situation. Although Algernon becomes very intelligent and can quickly run mazes and perform other tricks, because he is only a mouse, it's certain that he never understands what has happened to him and why. When Algernon regresses, he dies. Charlie, on the other hand, becomes even more intelligent than the scientists who conducted the experiment and figures out that the experiment is defective and that he will not be able to retain his intelligence. He undergoes the added suffering of being aware that his mental state is deteriorating. In the end, Charlie does not die, but he retains the memory of having once been smart, and this makes him unable to continue living around the people who once knew him as a genius.