THE SKULL is where we prêgress.
You might see that funny, lower-case letter E right above and wonder - why. That is to signify the phonetic spelling of the verb progress. Definition: advance or develop toward a better, more complete state.
Notice "perfection" was nowhere in that definition. As we progress in our training we may hit our goals, PRs, and even setbacks; but we always get back to the drawing board and plan for what tomorrow will bring.
The old you will never make room for the new you. You have to be intentional and deliberate about transforming your body, mind, and performance. Shed the doubt and redefine your self!