Laurel Canyon-mother son relationship

Watching Laurel Canyon for the billionth time, I thought I couldn't come up with anything new about the movie. But when presented with the term mother, I began to examine the relationship between Jane (Frances McDormand) and Sam (Christian Bale). As soon as the movie starts, you realize that the dynamics of their relationship are different from other mother-son relationships. Yes, she is not the typical mother. Yes, she does drugs. Yes, she can be seen as promiscuous. But Sam never says anything nice about her even though she is an amiable, at least, to people other than her son. With that being said, being a likable person doesn't make one the best mother. She is a person who is a free-spirit. It may have not been the best way to grow up, but Sam doesn't let her forget that. Jane has indeed messed up in the past. Sam, although seemingly grown up, acts like a child. He hasn't grown past his broken childhood. Sam insists that his mother has a development problem when frankly, he's just stuck on the fact that his mother didn't act like the person he wanted her to. She may need therapy as he says after he finds his girlfriend, Alex (Kate Beckinsale) in an unusual situation, but if she needs therapy, he needs it too. He is a product of his mother's upbringing afterall.
Sam's complaints in the beginning of the movie set the stage for what occurs in the movie. Alex is set up to be curious of a woman who she is told is a horrible human being, but when she meets Sam's mother, she comes to a different conclusion. Her confusion from what Sam said and what she sees creates more curiousity to find out what Jane's whole world is about, plus the fact that she's never experienced something so unstructured and unconventional. Yes, because of Sam's upbringing, he has become jaded of his mother and all that is associated with her, but that carries onto all other aspects of his life, especially in his relationship with his fiance. That is only natural, and anyone could see that if anyone knows anything about psychology.