In Zen Golf, PGA Tour instructor Dr. Joseph Parent writes about mastering golf’s mental game. The very first concept he addresses in the book is beginner’s mind:

Beginner’s mind is a mind that is open, eager to learn, an empty cup. If your mind is open, empty of preconceptions, it is always inquisitive, receptive to whatever arises, and ready to engage.

[N]o matter how good the instruction is, it is only as useful as the student’s interest and effort in learning.

Dr. Parent notes that Buddhist teachings offer an excellent analogy for the learning process:

Four types of cups symbolize four kinds of students. Instruction is symbolized by water being poured.
The first cup is upside down. This represents a student who is supposedly there to learn, but pays no attention. You may have experienced something similar while reading a book: Your eyes move across the words all the way down the page, but when you get to the bottom, you realize you were daydreaming and have no idea what you read. That’s what happens when a cup is turned upside down. No matter how much is poured, nothing gets in.
The second cup is right side up, but has a hole in the bottom. We hear what’s being taught, but we forget it all too soon. We don’t chew on it and digest it and take it to heart…This is the classic case of “in one ear and out the other.”
The third cup is right side up and doesn’t have a hole in it, but the inside is covered with dirt. When the clear water of instruction is poured in, the dirt makes it cloudy. This symbolizes the way we can distort what we hear, interpreting and editing it to fit into our preconceived ideas or opinions. Nothing new is actually learned. When we take a lesson, if the instruction matches how we already see things, it is taken as confirmation. Anything new that doesn’t match our opinion is resisted, ignored, or disregarded.
The fourth cup represents the ideal way to be a student. It is upright, receiving what is taught. It has no holes, retaining what is taught. It is clean, open to learning something new.