How has charlies opinion about Algernon change from the beginning of the story to now?

At first, Charlie despises Algernon for beating him in the maze. However, when he finally does beat the rat after the operation, he feels bad. He is permitted to hold Algernon and they quickly become friends. Soon, Charlie realizes what a strong bond connects him to Algernon. In a sudden turn of events, Algernon bites Charlie due to lack of intelligence, causing Charlie fear and sadness. When Algernon dies, Charlie becomes depressed, and he is aware that he will soon decline in intelligence, and maybe die also, knowing that he was once a genius.