The Hunger Games trilogy gave me bad dreams. Actually, the books provided images, feelings, and ideas that my brain used as ingredients to brew up nightmares about children’s bones floating in a river of red dust and creepy lizard mutts lurking in the storm drain outside my front door. My brain is good at that sort of thing. But dreaming wasn’t the only business my brain was doing while I slept. It was also forming memories. That is why I remember Greasy Sae’s concoction of mouse meat and pig entrails, Prim’s untucked shirt, and, of course, Katniss, the girl on fire.

You probably remember why Katniss called Prim “little duck.” It’s a detail that’s important to the story. But—unless you share my personal fascination with mice and nasty-bad soup—Sae’s recipe isn’t stashed in long-term memory. That’s because every individual has a unique brain in charge of selecting information and forming memories. Depending on our previous experiences, we notice some things and ignore others. In the process, we build an ever-more-specialized system for dealing with the world. We can donate a kidney or a chunk of liver or a pint of blood to someone else and those cells have a good chance of being useful, but the brain and the memories in it can’t be transplanted. Brains are weird, custom-made, do-it-yourself projects.

The Hunger Games is an especially good series to read with the brain in mind. Nightmares, memories, and hallucinations are an important part of the story—and all of those things are brain business. Why does Katniss behave as she does? I think the answer to that question depends upon understanding her brain, not her  …