Dad, what is the meaning of being alive?

Today, I had lunch with my son. Suddenly, he asked me, "Dad, what is the meaning of life?" Thinking he was just asking casually, I confirmed, "What did you say?" After he repeated the question, I told him that it was a very good question, so I answered it seriously. Including the Taoist advocating the unity of man and Tao, the Confucianism of investigating things to attain knowledge, self-cultivation, family harmony, state governance, and world peace, the Buddhism of realizing that all things are "empty" to transcend reincarnation and become a Buddha, the Christianity advocating knowing the highest God and glorifying God, and ultimately reuniting/being one with God. However, I also emphasized to my son that what I said may all be wrong, and he needs to think for himself what the meaning of life is. (Still in the fourth grade) So young, and already thinking about the meaning of life?!