Self-knowledge is the knowledge that one has of one's own thoughts, feelings, and experiences. It is often associated with concepts, ideas, and myths because these are the ways in which we typically represent and communicate our self-knowledge to ourselves and others. However, self-knowledge itself is not necessarily a concept, idea, or myth. It is a direct, experiential understanding of one's own inner state and being.
For example, when you feel a sensation in your body, such as a pain or an itch, you do not need to rely on a concept or an idea to recognize and understand the sensation. You directly experience the sensation and have an immediate, non-conceptual awareness of it. This is an example of self-knowledge that is not a concept, idea, or myth.
Self-knowledge can also be more subtle and abstract, such as an awareness of one's own thoughts and emotions. Even in these cases, however, the self-knowledge is not necessarily a concept, idea, or myth. It is simply an immediate, direct awareness of one's own inner state and being.