First, we are introduced to this small family of three, where mother [Arquette] is divorced and still tries to partner with the guy taking care of her children. This unsuccessful attempt results in those three departing to another city to make it work better. The next guy turns out to be tyrant, beating his wife and abusing children. So, this story also has no happy ending. While they are struggling, kids' father and ex-husband of Patricia's character - Ethan Hawke - is living his life, seeing children on weekends and holidays and doing the best of him to be a dad.
Film feels extremely natural, as if you are looking at real life of real people. The fact that actors grow up, get old and progress through one movie and you know that this is not fake, makeup or special effects, just aggravates sense of reality. On the other hand, it sometimes gets as boring as the lives of others [and ours too]. Regardless all the good stuff I'm gonna say below, Boyhood sometimes felt a little long [it's 165 minutes] and hard to follow.