What exactly do Lennie and George gain from each other's friendship?
I think that Lennie's needs are directly met through his friendship with George. Lennie comes to depend on George for protecting him and looking out for his well- being. From Aunt Clara to George, Lennie has always been dependent on someone overseeing him and safeguarding his interests, providing companionship, and ensuring that he is not manipulated by others in the world who have little problem in doing such things. In this, Lennie receives literal and immediate benefits from his friendship with George. In exchange, Lennie gives absolute loyalty and probably the closest thing to unconditional love that is possible. It is in this that George gains something from their friendship. George says as much to Slim in Chapter 3, when he talks about how he used to play practical jokes and deride Lennie until he actually say how serious Lennie takes what George says. This level of devotion and absolute loyalty in a world that is deprived of it is what George gains from their friendship. George, the product of the world in which he lives, recognizes through Lennie the ability to remain distinct from it, the ability to represent what can be as opposed to what is. George and Lennie speak of how they are reflective of "guys who look out for one another" and this is something of which others in the narrative take note as being distinctive and unique from what is seen. George gains this sense of being revered and of being loved in an unconditional manner. While George talks of being on his own and pursuing a life that is not so very tethered to the existence of another, it is evident that George gains much in way of emotional satisfaction from tending to Lennie and serving as his protective guardian. It is for this reason that George decides to take Lennie's life, as he is confronted with the reality that the lynch mob of Curley and Carlson would torment Lennie and take his dignity away. George's actions of being this protective figure are evident at the end, reflective in how he must be supported by Slim at novel's end. In this, one sees how withered George is, representative of how much he has lost with Lennie's death.