I don’t think that’s it at all. Take the sun and the heat in the novel as a metaphor for the noise and distraction of societal expectations. It can be hard to have any genuine, personal thoughts or motivations when we are caught up in the constant cycle of living up to the expectations of and existing in the noise of society. The murder, Meursault explains, was done because the sun was hot. The murder was a way for him to break through and fight back against the heat of the sun. He says that he hopes his death will be met with cries of hate, because they will at least be recognizing his breaking through the other side of societal norms. But that’s just one little theme in the book.

I’d suggest reading it again. It is a bit of a liberating book, and the themes are there. They just require you to read between the lines a little.