Interesting question I asked someone, "what do you know about yourself", the person said, "I didn't understand the context of the question"
The simple question was deep no doubt, if we start to know ourselves, we will know the world too outside us,
Imagine how our body works, how our blood pumps through the body, how we think, how our brain works, how we digest food and so many other processes in our body undergoing on a fraction of a second,
That is why we say, we are a beautiful creation of God because only something higher energy can create such a marvel,
We say we know the world in such a short span of life, but we fail to understand the processes going within,
Let's take a cell of our human body, the smallest unit of creation and life,
So many complex functionalities going within the cell, entire life within the cell of our existence, and from there we grow to the form we are,
We take everything for granted in life, it is happening because it is designed so and it has to happen,
We take our life for granted, our blessings for granted, our relations for granted, and even our existence for granted,
Why, when you in your entire life didn't know how you function, how can you be sure of knowing the universe and its existence,
That is why, it is always said to travel within and know yourself, if you know yourself then you will know who you are and what wonderful creation you are,
We can replace anything with modern medical science but we can never have the real and original structure and functionality,
Think...how much you know about you, then only try to know the world,
The one who doesn't know the self will never be able to know the existence outside, and the one who knows the self will always be in never-ending peace within and outside,
Realize your existence then only you can realize the existence around,
Stay blessed