Q1: Why reading is so important?
Life is short, and a person's experience is limited. Not only limited, but in most cases ordinary. Reading can help us appreciate other life experiences, different joys and sorrows, and foster empathy. Empathy is the way people connect with the world. Through reading, we acquire empathy, which lets us experience a broader world.
Q2: The book that made the biggest impact on you
There is no doubt that it is Cao Xueqin's Dream of the Red Chamber. Since senior grade of primary school, I have kept it at hand. I often say that if you read Dream of the Red Chamber thoroughly, you can have a better understanding of ancient Chinese society.
I can only say that reading is important to me. It brings new knowledge and experience. I precipitate change and renew myself every day by reading. Obviously, the more time you invest in reading, the more you gain. The real reward of reading is that it lets you be truly yourself. At the very least, you can enjoy a quiet time reading.
I think what George Martin said in his fantasy masterpiece, A Song of Ice and Fire, the origin of the HBO series The Game of Thrones, is the most appropriate answer to this question: A reader lives a thousand lives before he dies. The man who never reads lives only one.