There are real barriers, sure. No amount of 'positive thinking' will allow you to safely jump off high buildings. But having said that the usual first barrier for all of us is a mental one. We can draw. Possibly not as well as Michelangelo initially but we can have fun with it and might-with practice-get good at it. We can push back on unreasonable work demands. We can start our own enterprise. We can change our community for the better. It all starts with overcoming the mental barrier. It's then generally a long way until the real, physical barrier.