Why is it important to know that the stable buck, Crooks, has several books and reads a lot?

Crook's room is a small hovel connected to the horse stables. Crooks is fiercely defensive of it because it is the only space that is his own. He is not allowed anywhere else on "account of being black" In his room Crooks has a "tattered dictionary and a mauled copy of the California civil code for 1905". We can surmise that Crooks strives to be literate on his own. Crooks also wants to be aware of the few rights he has as a black man. Crooks is an intelligent man with little or no schooling but does what he can to better himself.