Status Updates From Psycho

Now the book's really starting to begin. "Mother's" already killed Mary and Norman being the momma's boy he is, tries to cover up for her. Why, is the only question I ask. After all of the emotional abuse she's inflicted on Norman, why?

"Mother, Oh God, Mother! Blood, blood!"

After watching the first three Psycho movies and reading the first two chapters of this book, I feel like I can understand Norman's character in the movie a bit more. Like the motive behind each interaction