16.

Imagine you’re eating a hamburger. Better yet, go to a nearby fast food restaurant and buy a hamburger. It’ll cost you eighty-nine cents. You go. I’ll wait.

Ready? Now lift the burger as you normally would, by the buns. Bring it to your mouth. Take a bite—not huge, not tiny. Bite as if you weren’t being watched. Rend as much meat, cheese, tomato, and bun as is comfortable for your particular mouth. Now chew. Concentrate on what happens inside there. Notice how the food shifts naturally, without conscious thought, from one side to the other? First, it’s kept near the front, dancing over the middle of the tongue. Those bumps—called papillae—each one of these bumps has taste buds on it. And the buds themselves are wearing wigs—microscopic microvilli, sensitive hairs that describe to your brain what you’re chewing: salty, grilled, fleshy; sour, tangy, sweet; metallic; ashy; acidic like bile; flavorless as glass.

Within seconds, your teeth do a decent job of pulverizing your bite. Enough so you can swallow, anyway. Your neck convulses as the wad of Burger King breeches the back of your throat. This morsel drops into your tummy for one last disintegration, the acid bath, which will transform it like a fairy tale prince into a frog of basic nutrients—vitamins, carbohydrates, fats, minerals. These will course through your tissues and blood. They will help you live.

But wait! Don’t let that bite go so fast. Bring it back up. With a slight flex of the epiglottis, a gesture similar to making yourself

belch, and with an additional heaving motion, a tightening of the back of your throat to kick-start the gag reflex, you can rescue that masticated bun and burger, welcome it into your mouth again. Ahh . . . there we go.

Chew it some more. You weren’t finished. It’s quite soft now, more pliant than gum. Spongy, to say the least. Ten, twenty more chews.

Then swallow.

But wait! Don’t let it go. Bring it back up. Run it through the courses a third time. Your saliva enzymes are doing their job. The mush is nearly liquid now, but you don’t discriminate. Ten chews. Slow ones. Swallow.

You’ve been holding the burger for five minutes. The teeth marks in the bun indicate you’ve only taken one bite. Your family is looking at you. You’re working on it. You haven’t finished chewing yet. They need to mind their own business.