Epistemology has nothing to do with understanding, which is a discipline known as hermeneutics, which has its origins in the study, and comprehension of scripture.

If you think of knowledge as a telephone book, and epistemology as the study of how we make and use such a thing; then you know epistemology. If you think of understanding as an intimate conversation with your lover, then you understand the difference between the two--as much as we can know anything.