The limit of your achievements is your imagination. Once you realize that the true creative power lies in the creative plane of the world, not the competitive, you understand that anything can be created through thought. Thus, thought becomes the limit to what you create or achieve.
The more you free yourself from learned behaviors that limit your imagination, the more you can become and create. This path is filled with uncertainty and ambiguity, but it's our natural journey of becoming—what we're meant to pursue.