a BIG qustion

Whenever I am free of homework or have nothing to do, I begin to think about the big question why we exist in space & time. I remembered talking the issue with my dad, my politics teacher and a couple of friends.
I was quite a little girl when I came to my dad with this question. Dad pretended to think for a while and answered me, ‘Well, it is really a huge problem. Before we go to this one, we should think about what the life is, which comes after the question how evolution works…’ I ran from him.
My politics teacher in high school is a wise woman. She taught us to not only think what is going on now, but also to image what we are going to do. To this question, in her words, there is no answer, or any response is the answer.
The question has been with me for many years and I was more curious to the right answer for me after I entered the college. This is a period of time I questioned myself and questioned what my future is like. I was unsure about my decision to choose my major as math, which seems not the right thing for a girl. I had 17 hours in math a week, 20 hours learning by myself. I had no idea what I could do with my knowledge. My mom thought I was silly since I bought her a pair of socks which turned out to be different in color. My hair began to drop and some turned white. Once again, I continued to consider this question carefully.
I still went to classes every day and finished assignments every week. But the question never disappeared. Gradually I became used to the content we learned even though it was too hard for undergraduate students, and I tried to be accustomed to the way we learned new things. I also went to many activities and met a lot of friends. It seemed that I was much clear about my goal and I felt myself fulfilled. No matter what I do, no matter where I am, no matter what kind of people I am with, I am sure where my destination is.
When someone asked me why I decided to transfer while I can find a good job and live a high standard life in China, I told them it is very important to make sure what you are doing and what you are going to do.