If we are asked to imagine how we would feel if we became paraplegic, we are apt to anticipate a terribly unhappy life, as Gilbert and other researchers have shown. If it actually happens to us, our psychological immune system fortunately helps us make the best of it, and we soon wind up feeling much better than we thought we would. The downside of this system is that it makes us poor predictors of our future happiness; the upside is that it makes us better survivors when life goes badly. But