On a wet spring day in London last week, I found myself in a plush Claridge’s suite with milliner Philip Treacy, just a little starstruck. You see, I am a hat lover. And Treacy’s designs, worn by Madonna, Lady Gaga, Sarah Jessica Parker, and, oh, the Queen, are iconic. We’re here to talk about his new limited-edition M.A.C. collection, inspired by a trio of couture hats: a sparkling Art Deco number, a green-and-pink spectator, and a full-on lace mask (above).