Why does charlie leave in Algernon?

In Daniel Keyes' novel "Flowers for Algernon," Charlie Gordon leaves his job at the bakery and ultimately decides to distance himself from his friends and coworkers after undergoing an experimental surgery that significantly increases his intelligence. As he becomes more aware of his previous mental limitations and the way he was treated by others, he feels alienated and struggles to connect with people who once were close to him. His journey highlights the complexities of human relationships and the impact of intelligence on personal identity. Ultimately, Charlie's departure signifies his need for self-discovery and the realization that his newfound intellect comes with its own challenges.