You went to pick out cheese, and I was passing through the bulk foods, and that's when I saw the pecans -- the shells a rich, grainy brown like those bookshelves my Dad built for me one Christmas. The stain was walnut, he'd said, but it looked much more like a pecan shell than walnut. I hadn't eaten a pecan in years, hadn't cracked open a pecan shell since I was a child and the house was filled with them. You don't believe me about those pecan exchanges, but my sister, Addie, has the same slide show memories.

Road trip, just Mom and us. Then hours later we're parked back-to-back with another car. We're beside a lake, no other cars in sight. Addie and I aren't allowed to get out, but we unbuckle. And I start to wonder what's going on, why we've driven so far, why so many bags of pecans are being transferred between the trunks of the two cars. But then the other woman hands each of us a Nestle Crunch bar, and Mom, who never let us eat candy, just reminds us to say thank you and not get chocolate on the seats. And we're brainwashed into not caring. Somehow I always forget to ask Mom about it. Once Addie asked, and Mom said the other woman worked for Nestle, but that's all Addie could remember. I don't imagine anything underhanded was going on. Either Mom was selling the pecans or buying them, I guess. But they were everywhere. In dishes where other people kept hard candy or coins, we had pecans.

So I filled a bag and put them in the cart, and you added the cheese and chicken breasts. And then when we were checking out, I realized I hadn't looked at the price of the pecans. But before I could slip away, the cashier was sliding items over the pad. Pretzels on sale, Detergent mismarked. And pecans -- $8.14. I had no idea they were so expensive. "Wait, can you take those off?" I said. You looked at me like I was crazy.

"Do you want pecans?" you asked.

"Yes, but -- $40."

"Do you have more than $40?"

Technically. "Yes," I said.

"Do you think buying the pecans is going to ruin your life?"

I didn't. I even laughed. The cashier rolled her eyes. When we got home, we didn't have a nut-cracker. Mom had at least a dozen. I had to run around the block to buy one. That's all we ate for dinner. Pecans and your mother's sponge cake.

Life changed after the pecans. At restaurants, we'd order soft drinks instead of water with extra extra lemon. We'd get cheese on our burgers. "Do you think that slice of cheese is going to ruin your life?" I'd ask myself. We'd meet the neighbors out for a drink instead of insisting they come to our place. I even bought a book once instead of going to the library. I didn't tell you for a week. But then you came home with a sweatshirt. A new sweatshirt.

I was up for a job at the Environmental Protection Agency and temping at UNC for the short run. It was your turn to go to grad school, and you still did some freelance work, but we couldn't be certain one of us wouldn't end up with a gap between jobs. And then one day when I was paying bills, I decided to chart our expenses. The computer drew columns for rent, utilities, insurance, student loans, food, and excess. Excess. The column was red. In November, we'd spent just $2.25 on excess: a four-pack of aromatherapy votives, I remembered. In February, we'd wasted almost $81. An increase of 3,485 percent.

I couldn't even speak, but I motioned you over to the computer. Student loans were one thing, but I was not about to start whipping out a credit card for groceries and restaurant tabs so that years later I could be paying off bills for things I couldn't even remember. That's what got my mother into trouble and my brother-in-law and your old college roommate. We'd discussed it. We agreed. I just stared at that bar, that huge red bar and felt my throat constrict, my lungs tighten. You glared at me, and I glared at the screen, and we both knew that asthma inhalers cost $27 each. I couldn't afford a refill this month. Stop, I told myself. Stop. But I couldn't. The more I tried not to think about my inhaler, the more desperately I needed it, so I pulled it out. You avoided my eyes. One puff. Two. Two was enough.

It's much harder to order water with extra lemon when you know how nice it is to get free refills of Dr Pepper. I returned my book after reading it, careful not to crack the spine; but from then on, library books smelled funny to me. You tried to return the sweatshirt, but they could tell you'd washed it already. So you kept it. But you didn't wear it much, then one day it was gone.

Now that you're in your second year of law school, you don't have much time for freelance work, and the EPA doesn't pay that much even though it's a steady job, so we allotted $32 per week for groceries. We take turns going. It's too difficult going together. We argue. I look forward to my weeks because I love the free samples: sometimes the fancy Swiss cheeses, sometimes fresh-baked breads. Once, chocolate chip pecan cookies. I didn't see the sign until I'd eaten the whole cookie. I had an asthma attack right there in the grocery store. But I didn't tell you. My mother bought the refill.

I can't think about the pecans without thinking about that look you sometimes get in your eyes, or the cold of the living room in the winter, or the taste of cheap cheddar. That's why I almost never eat peanut butter anymore, even though it's inexpensive and filling. It reminds me of the pecans. And Dad's bookshelf -- I had to bring it back to Mom's house. And the beach. That's why. The shells on the beach will remind me of pecan shells and pecans and that huge, awful red bar. And that night when we blindly ate sponge cake and pecans as if life could be so simple.