When I started my doctoral studies, I was talking with a professor who had just completed his. I was saying something about realizing how much I didn’t know as I was working through graduate level coursework. Quite pithily, he said, “Yes. When you’re an undergraduate, you think you know everything. When you're a graduate student, you realize you know nothing. Then, when you work towards a doctorate, you realize that nobody knows anything.”
Blaise Pascal said something similar in Pensées:
It is in the state of ignorance where man really belongs. Knowledge has two extremes which meet; one is the pure natural ignorance of every man at birth, the other is the extreme reached by great minds who run through the whole range of human knowledge only to find that they know nothing and come back to the same ignorance from which they set out, but it is a wise ignorance which knows itself. Those [undergraduates!] who stand half-way have put their natural ignorance behind them without yet attaining to the other; they have some smattering of adequate knowledge and pretend to understand everything. They upset the world and get everything wrong.
There’s also Socrates’ famous line: “I know that I know nothing.”
Of course these are extreme examples. But, they get at a truth: while it’s not true that we know nothing, it is true that there’s more we don’t know than we do.
Amen! Humility of Heart by Fr. Cajetan Mary Da Bergamo, 18thc, has 153 Humility checks like "What good qualities have we of our own for which we can praise ourselves?" Benedict XIV says his writings "have this rare quality in our day, that they satisfy the intellect and the heart".