Crooks's thoughts in the passage above from Of Mice and Menreflect the ideas of all the novelette's outcasts. Just like George, Candy, and Curley's Wife, Crooks longs for human companionship; he simply wants another person to acknowledge his existence. Likewise, George thinks that he and Lennie are different from all the other lonely migrant workers because they have each other. George's actions mirror Crooks's words--George knows that Lennie isn't listening to him most of the time, but he (like Crooks) simply wants someone to hear him. Similarly, Candy is willing to invest his life's savings in strangers' dreams so that he can spend the last years of his life with others. His one companion, his dog, is now gone. Finally, Curley's wife is willing to risk the fury of her abusive husband just for human conversation. Her behavior with Lennie is exactly like Crook's conversation with Lennie; she does not care that Lennie doesn't understand her.
Crooks's race is the reason for his isolation, just as Candy's age and handicap isolate him, and Curley's wife's gender forces her into a solitary life. Because of his race, he must live outside of human contact. Because of his race, he no longer trusts that dreams can come true. Steinbeck devotes all of Chapter 4 to Crooks to illustrate how completely isolated the stable hand truly is because of his race.