I tend to enjoy myself quite a lot when I swim. And yet, I would very rarely choose to swim when the opportunity was available. One might conclude from this that though I liked to swim, I didn't want to swim, so my "wanting" and "liking" were out of sync. But on further reflection, something more subtle was occurring. When I would try to decide whether I wanted to go for a swim, I would do so by performing a quick mental simulation of the experience. The problem was, that in the case of swimming...