He is lonely because he is black, which means that he has to live and sleep separate from all the other guys, because racism was the status quo at the time. Crooks is very bitter about life because of this isolation and loneliness which is shown abundantly through his personality. He isolated himself because that’s the only interaction that he's had with the other people who come and go through the farm. When Lennie comes the the barn in Chapter 4,he at first maintains his bitter exterior that he has been conditioned to maintain. As the conversation progresses, he lets it down showing his joy to have someone to talk to, and be with. This shows that without companionship, people can put up barriers to keep other people out and they can have a bitter, pessimistic outlook on life. This, however, is not always the fault of the lonely person. In Crooks’ case, his already pre-set social standing that he was given when he was born is the reason that he has to go through the loneliness and isolation that he does. This racism that he suffered is easily shown through his quote, “‘Cause I’m black. They play cards in there, but I can’t play because I’m black.” Crooks is the most tragic of all characters because he is never given the chance to change how he’s treated, and he won't ever be able to change it because racism was acceptable in this time