Candy and Crooks are in similar situations. Both men are rejected by the ranch hands. Candy is getting old and he knows it is a matter of time before he will banished for being no longer useful:
Candy is the old, disabled ranch hand who is helpless to stop the shooting of his dog and who knows that he too will be banished when he is no longer useful. He is sweetly hopeful of joining Lennie and George on their dream farm, offering to contribute his savings of $350 to buy the farm.
Because Candy is becoming less useful, he realizes that his time will be up and he will be put off the ranch.
Crooks is ostracized because he is black. He cannot even sleep where the other ranch hands sleep. He is excluded from the activities that the other ranch hands enjoy:
Crooks, the despairing old Negro stable worker, lives alone in the harness room, ostracized from the ranch hands.
Both Candy and Crooks understand what it feels like to be treated as an outcast. Both men feel worthless in the sight of the other ranch hands. Regardless the hard work that either has contributed, each man feels a sense of not being wanted.
Crooks is so bitter until he tears down Candy's dream of joining Lennie and George in their dream home. Crooks is certain they will never attain their dream:
On the one occasion when he briefly talks to Lennie and Candy, the bunkhouse worker who wants to be part of the dream farm Lennie and George are planning to buy, Crooks tells them they will never attain their dream.
Crooks is just being realistic in a cold, cruel world. Crooks and Candy have no one who really appreciates them. The ranch hands see no real reason for keeping either of them around. Both feel a sense of rejection. No one gives them self worth. Both Candy and Crooks live in a type of isolation from the other ranch hands.