I’ve never become more than a modestly competent skier – capable of safely negotiating most intermediate slopes, but frankly way over my head when I venture onto anything more difficult. Slopes with deep moguls, ice, or the dreaded diamond are, well, nerve-wracking. When I start down, with the ground dropping away under my feet and nothing in sight but blue sky, every instinct in my body urges me to lean back. Now, those of you who ski know that that would be a disastrously bad move.