Is self-knowledge the understanding of something we call the self, which is the permanent...

Is self-knowledge the understanding of something we call the self, which is the permanent, or is it learning about the movement of the self? The former is to study something that is there, like the microphone – I can study it, learn about it; it is there. Now, is the self ‘there’, or is it a movement, a thing that is constantly in motion, therefore not permanent? So one has to find out if the self is something that endures, permanent, or if it is something that is constantly in motion, constantly changing. So, is self-knowledge the knowledge of the self which is permanent, or the understanding of what the self actually is?