The self is a very deep, bottomless pit. I can never see myself clearly because I can never be sure of what I will think of next moment.
I understand all my past, hopes and plans for the future, as well as my desires, dislikes, and preferences... But what I cannot be certain of is what I will think of in the next moment after each thought process ends, or how I will react to sudden events. These are all highly random, so getting to know yourself is something that can never be completed. However, on the path of self-discovery, one will never stop their steps.
What is the self composed of? Memories, desires, and the active consciousness. They correspond to the past, future, and present respectively. The self is like an airplane in the sky, with the active consciousness as its engine, desires as its steering wheel, and the past history (memories) as its trail.
Who is a person without a past? Indeed, people understand you through your past, but your history and past cannot fully define you, just like the poop you pull out cannot fully define you. If you don't think so, then you are just a prisoner of the past. What defines who you are is not just the experiences you gain from your past history, but also your dreams and plans for the future. What truly defines who you are is the active mind in the present moment. However, even you cannot fully decide what you will think of in the next moment, only the Creator can. So, from this perspective, what defines who you are is the result of the combined forces of the environment, yourself, and the Creator.