The questions about sex that the child asks are thus not— at a fundamental level— about sex at all. They are about the meaning of the body, the terror of living with a body. When the parents give a straightforward biological answer to sexual questions, they do not answer the child’s question at all. He wants to know why he has a body, where it came from, and what it means for a self-conscious creature to be limited by it. He is asking about the ultimate mystery of life, not about the mechanics of sex.
[…]
Sex is a “disappointing answer to life’s riddle,” and if we pretend that it is an adequate one, we are lying both to ourselves and to our children.

— Ernest Becker, "The Denial of Death"