If you want to improve, be ...

If you want to improve, be content to be thought foolish and stupid with regard to external things. Don\'t wish to be thought to know anything; and even if you appear to be somebody important to others, distrust yourself. For, it is difficult to both keep your faculty of choice in a state conformable to nature, and at the same time acquire external things. But while you are careful about the one, you must of necessity neglect the other
If you want to improve, be content to be thought foolish and stupid with regard to external things. Don't wish to be thought to know anything; and even if you appear to be somebody important to others, distrust yourself. For, it is difficult to both keep your faculty of choice in a state conformable to nature, and at the same time acquire external things. But while you are careful about the one, you must of necessity neglect the other

Quotes from the same author

Men are disturbed not by things, but by the view which they take of them.
It is the nature of the wise to resist pleasures, but the foolish to be a slave to them.
Keep silence for the most part, and speak only when you must, and then briefly.
Know, first, who you are, and then adorn yourself accordingly.
We have two ears and one mouth so that we can listen twice as much as we speak.