This is a really good book. That's really all you need to know, isn't it? Go out and read it!

Here's my brilliant insight about the book (mild spoiler warning!!!):
It resembles David Copperfield. There are many striking parallels. But it is in no sense derivative, it definitely stands on its own merits. Here are some of the similarities:

In both novels the protagonist is a journalist. He had a troubled childhood. His parents are dead. He makes a bad marriage to a foolish woman who dies young. He has a spinster aunt who helps him find his place in the world. The theme of child abuse is central to both stories. By the end of each book the protagonist is able to form a mature, loving relationship with a woman who is worthy of him.

This being said, the novels are very distinct. The style of writing, the mood, the empathy that you feel for the hero -- these are all very different. There is no way that Proulx is trying to write a dickensian novel. But these similarities are interesting, and probably not accidental.