Jake can’t truly be with the woman he loves (Brett) because of his impotence as a result of an injury during WWI. Brett may love Jake, but she knows she couldn’t be faithful to him because he couldn’t satisfy her sexually. Both of their lives were destroyed by the war in different ways. Jake’s friends have also been damaged by the war, in different ways.

There are activities they can still enjoy, but never again in the same way. Their innocence is gone.

The bulls and bullfighters are important to the story, too. But I’ve only read the book once (although recently) and don’t feel like I got everything from it that was there.