There is a mitzvah, commandment, for every Jew to write a Sefer Torah, a Torah Scroll. The purpose is that every Jew should know the whole Torah. For a Jewish king, there is an additional mitzvah to write a second Torah scroll and have it with him always. This verse teaches us a prohibition against a person being arrogant. A person who has arrogance will automatically have many other faults.
Arrogance can only come from blindness to reality.
Humility is recognizing and appreciating that all you have is a gift from the Almighty. Every child works hard to learn how to walk. He crawls, he stumbles, he falls, but eventually he usually succeeds. In truth, it is no different with any other of our accomplishments. Where people of all stages of life can explore and find answers to life's questions.