How is knowledge acquired?
Knowledge is aquired through experience (I don't limit the meaning of "experience" to the kind we get by doing the same thing over and over so that we become good at doing it; I use the word in the widest sense, meaning all that one goes through). If you have not experienced something, then you don't understand what that is. If you have not experienced something in the past, then you do not have any knowledge or concept about it. (Reading about what others have experienced is also an experience, although indirect and therefore limited). I will explain this using a few examples.
Think of a toddler watching a burning candle. He is attracted by the beautiful flame and wants to touch it. His parents shout, "Hey, don't! You'll burn your fingers." But the child does not have any past experience of getting burnt, and does not understand what his parents are shouting about. He thinks, "there is something bright and beautiful like a flower, and I only want to touch it. These people will not let me do it, but I am going to touch it anyway!" and crawls towards the flame and grabs it. "Yeowww…" From now on, he understands what "getting burnt" means.
Another example. If I tell you "cat", immediately you get a mental picture of a cat. It is almost the same picture that I have in my mind too. Why? You (or both of us) have had prior experience with cats. You have seen a cat, and probably touched one. Or you have at least seen pictures of cats. In your childhood, somebody showed you a real cat or a picture of it, and said "cat". When you hear the word cat, all these earlier experiences come back to memory. So you know, so you understand. If I now say "cow", it's the same. You understand. You immediately imagine a cow. But now if I tell you that I saw a "kakookah" yesterday, what mental picture did you get? You did not understand. Your reaction will be "Kakookah? What's that?" This was not your reaction when I mentioned "cat" or "cow." Why? You have never before heard of a "kakookah". You have not seen one, or even a picture of one. No one has ever before mentioned about a "kakookah" to you. You don't have any past experience with a "kakookah." So you do not know. So you do not understand. (I hope there is no animal by the name "kakookah" in any language!)
Suppose you are trying to explain your experience of getting an electric shock to another person. If that person has never experienced an electric shock before, what does he understand about your plight? Nothing. But give him an electric shock; then he understands. I don't mean he will become knowledgeable about the theory of electric currents or anything. But he now "understands" at least how shocking an electric shock is!
What do you think?