Charlie's view of himself changes significantly in Flowers for Algernon. Ironically, the more intelligent he becomes (as a result of the operation on his brain), the unhappier he becomes with his life.
The problem he experiences is that, as he gains intelligence, he becomes aware of several things that he wasn’t aware of before. For one thing, he realizes how slow he was mentally before the operation (or “operashun” as he wrote it). He looks at the man he was with something like disgust or shame. He also realizes that others who he thought were his friends actually took advantage of him and made fun of him at his expense. These realizations make it difficult for Charlie to feel true happiness.
Hey there, Vocabulary,
You'll need to be a little more specific to which 'Charlie' from which text you're referring to. Unfortunately, there are too many characters named Charlie out there who change to specify the novel you're talking about.