George's decision to stay with Lennie in "Of Mice and Men" is driven by a complex mix of responsibility, loyalty, and hope. Throughout the novel, it becomes clear that Lennie has a mental disability and relies heavily on George for guidance and protection. Despite the challenges of caring for Lennie, George recognizes that he is a loyal friend and cares for him deeply. As he explains to Slim, "He ain't mean...he's jus' like a kid" (Steinbeck 43). This shows that George understands Lennie's limitations and loves him for who he is.
However, George's decision to stay with Lennie is not only based on a sense of responsibility. He also believes that their shared dream of owning a farm and living off the land is achievable if they stick together and work hard. As he tells Lennie multiple times throughout the novel, "We'll have a big vegetable patch and a rabbit hutch and chickens. And when it rains in the winter, we'll just say the hell with goin' to work, and we'll build up a fire in the stove and set around it an' listen to the rain comin' down on the roof" (Steinbeck 15). This dream provides a sense of hope and purpose for George and Lennie, and it motivates them to keep moving forward despite the challenges they face.
In short, George stays with Lennie because of a deep sense of responsibility and loyalty, as well as a shared dream of a better life. Despite the sacrifices that come with caring for Lennie, George recognizes that his friend is worth it, and he is willing to do whatever it takes to protect and support him.