“I tore open a bag of truffle chips---really truffle-flavored potato chips---that cost $3.95: a novelty I'd never buy on my own. I shook them onto a small plate and the scent of truffles, at once earthy and faintly metallic, filled the air. That scent always triggers a free-floating longing in me, the ache of a bittersweet memory, but with no specific memory attached. (Did such poignancy make the chips worth twice as much as the Lay's?)”