No matter how much you learn, you’ll never know everything. The more you learn the more you realize how much you don’t know.
There’s no way for you to know everything, even about a single subject. You could spend your entire life specializing in one area of study/practice and still not have all of the answers.
At some point each of us has to let go and accept our deficiencies and put some measure of trust in something outside of ourselves. Reality rejects any person who thinks they know everything or is above others because of what they do know.
Don’t beat yourself up if you feel that you don’t know as much as other people, nobody knows as much as they think they do. And a person of true knowledge knows that anything he or she does know is a gift.