Something is wrong in our culture. This film is a painful reflection of that fact. Self gratification is the best part of the day. Mr. Burnham narrates the last few days of his life from the other side of the grave. He is trying to tell us what is important.
Children sometimes suffer too much from the emotional silence of their parents.
In this film mom is gone. And, dad is having an emotional response to the daughter's best friend. This is an interesting question that the film raises. Lust, passion, greed, love, hate are all strong motivators. For Mr. Burnham the goal of having sex with a blonde cheerleader was the driving force to improve his physical appearance.