Preface: When I first wrote about this topic, I was 16 years old, and I was only in my second year of high school. The depression of adolescence after I grew up made me miss my childhood days. I was almost overwhelmed by books at that time, so naturally I couldn't write down the story of this topic. In a flash, I am 26 years old, and ten years have passed. What I miss is still my happy childhood days.
I should be happy, at least the only feeling of happiness I have now is left over from that time.