Almost everyone on the farm is lonely and the person that represents this the most is Curley's wife, one of the most pivotal characters in the book.
I feel Curley's wife is the most despairing and lonely character in the book. She has no friends, no future, no respect; she doesn't even deserve a name.
I really feel sorry for her, all she wants is someone to talk to, to converse with but in her mind the only way she can do this is by flaunting herself to the men just to get noticed. This leads her to be judged as a 'tart' by the men.
I think she represents absolute loneliness and desperation to achieve something better in life.
Curley's wife desires to become famous and be a star, to be noticed by everybody. When she was fifteen she wanted to become an actress but ultimately she couldn't.
'I tell ya I could have went with shows. Not jus' one, neither. An' a guy tol' me he could of put me in pitchers...'
This feeling of 'I could' appears to be one of the major factors of why she's unhappy. Her unrealized dream of being in the limelight leads her to marry Curley to act as a sort of compromise since being the wife of the bosses son may have given her some respect and some luxuries in life.
One aspect that relates to all the other characters in the novel is the loneliness that engulfs her life and her total failure to find companionship.
Curley's wife has no friends on the ranch and her 'passion' to communicate with anyone makes her attempt to try and find some kind of sympathy with lowly regarded people such as Crooks or Lennie.
Curley's wife's search of company leads her...