In Of Mice and Men, why does George stay with Lennie?

's
Aunt Clara andknew each other; after she died, Lennie started traveling around with George.
George also likes having Lennie around.

When he's asked why he stays with
Lennie, George says he stays with Lennie because it's nicer to travel around with someone you
know. Slim finds it strange that he does so, saying that other guys don't travel around
together.

George explains that both he and Lennie were born in Auburn. Clara
adopted Lennie when he was a baby. Once she died, Lennie started traveling with George. Though
it's not said directly that Clara asked George to take care of Lennie, it's somewhat
implied.

Later on, George reminds Lennie not to run so fast because his Aunt
Clara wouldn't have liked it. Lennie also remembers his aunt and says that she gave him a piece
of velvet to pet. He also hallucinates a vision of her later in the story.