Curley wrath, pride, and lust
All I wanted was... to be a man, to be with a with a woman, to control everyone, to show my strength, and to beat up big guys,
But I never wanted... to lose a fight, to be weak, to kill someone, to destroy his wife's dreams, and to get his hand broken,
In the book, the characters talk about Curley keeps one of his gloves full of Vaseline. Showing one of Curley's weaknesses is lust. Curley said," I'll kill the big son-of-a-bitch myself." Showing he would kill for his wife.
Curley said to Carlson," You keep outta this les' you wanta step outside." The narrator said,"Curley stepped over to Lenny like a terrier." Curley said to George,"What the hell are you gettin' into it for?" For the most part Curley is confrontational and violet with everyone in every scene.
If Curley wasn't in this novel then his wife wouldn't either, so the fight between him and Lenny wouldn't have happened. Also the death of Lenny and Curley's wife wouldn't have happened.