"If you wish to improve, be content to appear clueless or stupid in extraneous matters. Don't wish to seem knowledgeable. And if some regard you as important, distrust yourself."
(Enchiridion, Chapter 13)

A Stoic quote about focus comes from Epictetus, emphasizing the importance of directing our attention and effort toward what truly matters:

This quote reminds us to focus on our own growth and inner discipline, rather than being distracted by trivial or external concerns. It calls for prioritizing what is within our control and letting go of the desire for external validation or superficial pursuits.