There is a saying, "Golf can't be taught, it can only be learned". That doesn't mean we can do without a coach. The point is that no matter how good the coach is, he or she is only as useful as the student's interest and effort in learning.
A Buddhist master likes to use the cup as a metaphor of a learning process. Four types of cups symbolize four kinds of students. Passing the knowledge 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 digest it and take it to heart: the classic in one ear and out the other. For example we might attend a golf school and when we get home our friend asks: "What did they teach?" and I reply "Hmmm, well, it was... I don't remember."
The third cup is right side up, doesn't have a hole in it, but the inside is cover 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 ignored.
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.
What kind of student are you?