My friend Wendy has always been the envy of our group of women friends. Willowy-tall, she has legs that go on forever, naturally blond hair, and a face like a model’s. Yet when she turned 50, she began to notice those little flaws that vex every woman of a certain age. In her case, droopy eyelids became the focus of intense dissatisfaction.“Look how this lid makes it hard to open my eye all the way,” she said a few years ago, as I drew close. “I’m thinking of getting surgery to correct it.”I was taken aback. Wendy was gifted with so many physical charms, and to risk going under the knife for one tiny imperfection seemed vain. Why meddle with nature’s course?And yet soon after, I felt the sting of judgment myself in the office of my dermatologist, an opinionated, hilarious gay man. For 15 years we had bonded  over my precancerous sun spots. But on this particular day, he looked into my face and frowned. “You know, I can take care of those crow’s-feet,” he said. “And you might want to consider some lipo for your tummy.”Indignant, I replied: “Why would I want to do that?”He smiled: “Um, so …