Of Mice and Men thrives on the notion that everyone is isolated, and everyone seems to get along quite well together by talking about how isolated they are. Isolation in this novella is much more an abstract concept than a reality – the men are constantly together and chatting. It’s the specter of having to move, to hit the open road again, make new friends, new enemies, and keep finding yourself all over again that seems to plague the men. These transitions (and having to go at them alone, by nature of the transient migrant worker lifestyle) are enough to make a guy feel isolated, even when he’s surrounded by people.
Although they are together, George and Lennie are always isolated from the rest of the world.
Because they are together, George and Lennie are never isolated. This is the knowledge that keeps each of them going.