It is not good because it leads us to believe that the past determines the present, which is a mistake. The past does not exist. The present is indeterminate. Everything that exists physically in the present is constantly changing so nothing is in this or that determined way, but everything can always change and will always change. To believe that the past determines the present is to believe that the present is determined, ergo, it is unchangeable, which leads us to a fatalism in which our decisions are futile because the present, and the future, are already predestined.

Many people say things like "I am like this because that is how my parents raised me", but it is not true, you are like that because that is how you decide to be, because there are a lot of decisions you are making, right now, without knowing it, that make you as you are. It is not that the past affected you and you cannot do anything to change it. The past does not exist, and the only reason why you are like that is because you have decided to be like that, because in the present, you are giving power to the past and not to the things you can do. There are many things you can do to change, but many times we forget it because we believe that everything is already written.

What makes you "who you are"?

That's something deeper. I don't think that most people know who they are, that's why most people define themselves by what they are not. They define themselves as from this or that country, this or that ethnic group, profession, lineage, belief, religion, etc. Not because that is what they are, but because that is what differentiates them from others, because that is what tells them what they are not. They are not from these other countries, nor from these other ethnicities, professions, etc.

Know thyself says the old maxim, know who you are, know what you are.

Maybe I don't know myself either. But what I believe is that whatever I am, that essence, that being, is completely inexpressible, there are no words to answer that question because there are no words that resemble what I am. I would have to invent neologisms to get closer. It is something that I am and that I cannot say, that can only be known, and that I know because when I see myself I recognize myself, and when I see what is mine and what I produce, I recognize it as mine, because it came from me, and it is my production. And anyone who knows that essence that I am, will be able to recognize me and mine because knows me and knows what I am.

So maybe I don't know what I am, or maybe I do and can't say. But in any case, nothing makes me whatever I am except myself. There is nothing outside that makes me what I am, I just am and nothing else.