There are two types of understanding, lexical and factual

[Sunclarity]

I've heard countless times, including from myself, that understanding was present. I thought it was because the words used by me and those I talked to seemed to reflect that. For instance, we all say alcohol, cigarettes and junk food are detrimental to our health. Yet, most consume one of those. Why? If we understood for real that it led to pain, we would at the same understand that which led to joy, and understanding that, we would feel joy and do only the things that brought it to us.

Thus, we don't understand for real, or factually, but to say we don't understand at all seems inaccurate for, if we didn't understand at all, we wouldn't be able to use words in order to describe it. This whole situation can then explained in terms of levels or types of understanding. One allows one to talk about it, to use words, the other allows one to actually feel and know. I can put this in another way. Imagine you memorized a book on advanced physics but didn't understand it. You memorized well though, so you are able to answer any questions through words.

But you don't understand. It's just music or poetry with no meaning behind. Lexical knowing is like that. Factual lets you aply and may or not involve lexical. I don't write this to discuss. If you think I am wrong, I will do no efforts to prove myself right.