I imagine the greatest challenge for any parent is your tolerance and ability to change with the times. As you look at a world framed with your experiences, I imagine you long for the world in which you grew up while thinking those were simpler times. "20th Century Women" is exactly about this battle. On one hand, we see a mother trying to embrace a new way of parenting her child. On the other, we see a woman who is the product of her environment. As the struggle grows, she turns to the community around her for assistance. Here is where the drama is introduced and we non-parents are given supreme insight into the world of what it takes to raise a child in a modern world.
There is another struggle parents face beyond their style. It is profoundly and beautifully stated in this movie and focuses on not knowing your children in the world. From the moment children leave your arms, they begin to create themselves. They carve out their own identities and personas. Much of this transformation goes unseen by parents because as children we conduct ourselves differently around our parents. In an essence, we aren't our true selves. We put one foot in the world of our choosing and another foot in the world of least possible conflict with our parent's ambition for our lives. This movie, better than any other, explains this dance.
I say this as someone who is not a parent and has no real desire to be one but I think if one wants to truly be a good parent then they must decide to be there. They must decide to be present. Your child will face untold obstacles in their life. They will fail and succeed. They will fall and need to be told to get back up again. They will need a cheering section and someone offering an alternative path. If a parent can successfully fill these roles, then they are on their way to creating a pretty decent person. "20th Century Woman" demonstrates parenthood better than any movie I have ever seen. For this reason alone, I highly recommend seeing it.
Be good to each other,
-Nathan