Why Did Crooks Go Through So Many Attitude Changes In Part 4?

One of the big things that happened in Part 4 was the conversations between Crooks, Lennie, Candy and Curley's wife. But what changed throughout the scene, was Crooks' attitude. At first he was not welcome to the prospect of talking to Lennie and seemed to view him as the big crazy new guy. But he begrudgingly invites Lennie in anyways and begins to talk to him. But what I found most interesting was that maybe Crooks didn't have the best intentions with Lennie when his " face alighted with pleasure in watching [Lennie's] torture"(71). A small hint of resentment towards his superiors came from Crooks as he began to pick at Lennie under the guise of a conversation. And because of this it seems like this will be yet another person picking on Lennie. But then Crooks apologizes for his hostility and even shares more information about himself. Then Candy arrives and Crooks goes back to his corner and assumes his harsh personality. But when Candy and Lennie convince him that they can and they will make their own place, Crooks offers that if they want, "'a hand to work for nothing-just his keep"(76) then he could come and help. And then he goes through yet another change when Curley's wife comes in and when Crooks tries to defend the other guys, she threatens him with her power and Crooks "stared hopelessly at her then he sat down on his bunk and drew into himself" (80). And then last of all was when he came "slowly out of the layers of protection he had put on" (82). All of these different versions of Crooks shows us just a small hint of all of the personas that Crooks puts on to protect himself from everyone else. But he is still lonely from all of his isolation and deep down all he wants is for some friends and some company. I think that Steinbeck added this scene into the book not only to help give us more context with Lennie and to move the story along, but he also addresses other problems and gives the only black person in the book more depth, especially when other authors in that time may not have. It also helps to show how much everyone else on the ranch beats him up and takes him for granted. What did everyone else think about Crooks in this part and the different ways he acted?