A problem with the concept of performance in Western society is that we often make the tacit assumption that if we spend enough time and effort on something we can master it. Hence, many books assume that identifying desirable states or conditions—productivity, collaboration, innovation, commitment—and suggesting steps for achieving them, is all that is necessary for mastery. My experience suggests otherwise. If your tacit or explicit mental model says “I can’t do math” don’t you think that steps taken to learn math skills might be influenced by that belief? Continuing with this thought, I would argue that in the vast majority of situations our inability to do something is limited at least as much by our beliefs about ourselves than our actual ability to do math. In other words, our mental models obscure the relationship between functional ability (what we can actually do) and capability (what we could accomplish if we were not encumbered by self-limiting mental models). So, if you really want to change your life and enlarge your capacity beyond what you believe is even possible, spend at least as much time challenging your beliefs as you do practicing skills. Otherwise your efforts may be against the gravity of false beliefs.