“It is impossible for a man to learn what he thinks he already knows.”
Welcome back to Mid-Week Meditations, Lifehacker's weekly dip into the pool of stoic wisdom, and how you can use its waters to reflect on and improve your life.

This week's stoic quote comes from the Greek philosopher Epictetus, who was born a slave and had his teachings written down by one of his pupils. Those writings would eventually become his Discourses and Enchiridion.
"It is impossible for a man to learn what he thinks he already knows." -Epictetus, Discourses, Book II, ch. 17
Another translation:
"What is the first business of one who practices philosophy? To get rid of self-conceit. For it is impossible for anyone to begin to learn that which he thinks he already knows." -Epictetus, Discourses, Book II, ch. 17
What It Means

Be it a skill, craft, or just general knowledge, to improve yourself is to learn. But you cannot learn if you believe there is nothing left for you to learn. What if what you know is only one of many possibilities, and some are better than others? What if what you know could be further enhanced by what others know? What if what you know is actually wrong?

If you do not show humility and approach all things as an empty, willing vessel, you will not grow. Never assume that your mind is full, or that what you know overpowers what others know. After all, how could progress be made in any field if everyone assumed they knew everything as soon as they learned something? It's arrogant and foolish, even for those who are at the top of their field.

What to Take From It

No matter what you pursue in life, keep yourself hungry to learn. Choose to always have a beginner's mind, constantly looking for another angle. Get comfortable with being wrong, and relish it when it happens. It's okay to be wrong as long as you make it a lesson. Don't be afraid to ask questions and seem like an amateur. An open mind can be your greatest asset if you let it.

We are stubborn creatures who would like to assume we're smarter or more capable than others, but hoping you're superior makes you inferior. Ditch the ego and accept your place as an eternal student. Besides, nobody likes a know-it-all, and true "experts" are the ones who will admit when they don't know something. Why? Because they'd like to learn it.

You can read the entirety of Epictetus' Discourses for free here.