But Trader Joe’s is no ordinary grocery chain. It’s an offbeat, fun discovery zone that elevates food shopping from a chore to a cultural experience. It stocks its shelves with a winning combination of low-cost, yuppie-friendly staples (cage-free eggs and organic blue agave sweetener) and exotic, affordable luxuries — Belgian butter waffle cookies or Thai lime-and-chili cashews — that you simply can’t find anyplace else.