MY BIG QUESTION

What sets us different from each other when we are all the same underneath? I know there's a lot of factors involved like personality, culture, and environment. There are many more than what I'll typed so far but my real question is how do we pick up these things? How do we get our personality? Can we change it? Is it even possible? I don't know. How can some people be more afraid than others? Why are some people smarter than others? Do we pick it up along the way or is some or all of it embedded into us? I mean we are just random if you think about it in scientific point of view. We get half of our genes from our mother and the other half from our father. To top it all off those genes are selected at random. We are all random humans. How does that make you feel knowing that your genes and body were selected at random? Can all my questions be answered? Who knows? Maybe in good time they will. Or not. We still have questions left unanswered to this day and age. It seems like when we answer a question a new one rises. It goes around in a circle. Will there be a time where no more new questions are asked? If we had the answer to every question how will that affect life? Our life? Society?