A few years back, I thought I’d stumbled upon the fashion holy grail — a flattering pair of jeans. When they started to disintegrate a few months ago, I thought I’d head back to buy the same style in the same size. Simple, right? But when I tried them on, I felt like I’d fallen into a funhouse mirror. The “same” size jeans had shrunk (yes, new jeans are tighter than well-worn ones, but this was extreme). When I returned them, the staffer behind the till told me she’d had the same problem — and that she now goes two sizes up as a default.