"When childhood dies, its corpses are called adults"

This quote by Brian Aldiss talks to the idea that the adult years is a kind of death of youth. It suggests that when we end up being adults, we lose something of our youth innocence and happiness. We end up being more serious, more responsible, and more familiar with the world around us. We end up being more knowledgeable about our death and the effects of our actions. We end up being more familiar with the extreme truths of life and the need to make difficult choices. We become more familiar with the requirement to work hard and to make sacrifices in order to achieve our objectives. In other words, their adult years is a kind of death of childhood, and the corpses of our youth are the adults we end up being.