In Of Mice and Men, one strength is the companionship that George and Lennie share. George and Lennie need one another. They find comfort in the company of one another. Their relationship helps ease the loneliness that ranch hands experience, moving from ranch to ranch, never having a place to call home. Truly, George finds strength in the fact that Lennie needs him. Even though he is often frustrated by Lennie, George really wouldn't have it any other way. It is comforting to be needed. When George criticizes Lennie, making him feel in the way, Lennie offers to go off by himself and leave George alone. George realizes that he needs Lennie:
When Lennie offers to go off by himself, George recants and says they have to stick together. Together they have someone to care about them and they have a future, a dream of owning their own farm with rabbits that Lennie will tend.
Truly, George enjoys having someone with which to share his dream. Each time Lennie makes a request, George retells the dream with enthusiasm. He cherishes the fact that he has someone who needs his dream to become a reality. Lennie dreams the same dream that George dreams. They have a common goal. They have a future together.
A weakness in the novel is represented by the dreary circumstances of the life. Always being on the move is a negative way to live. Because of Lennie's mentality, George and Lennie are always in trouble--always on the move. This causes George and Lennie to never be able to put down roots. They experience the loneliness involved with always being on the move. There is no stability in their lives. Before they can establish a sense of belonging, Lennie will cause trouble and George and Lennie will have to get out of town. This frustrates George. That is one reason he dreams of permanent quarters. George realizes that he and Lennie need their own place, a place where no one could run them out of town.
In the end, George realizes how much Lennie's companionship has meant to him. After having to shoot Lennie, George does not have the will to follow through with his dream. Without Lennie, George cancels the dream. Lennie was a real strength to George. Without Lennie, George's strength is gone. George will understand real isolation at this point.
One weakness in Of Mice and Men is that even though one of the centeral themes is the cruel treatment of migrant workers, Steinbeck does not directly show that.