I remember as a child, I'm not sure what age, but I remember it, so likely between eight and ten - I must have asked my mother a question about sex. I don't know when it was, but I don't remember her answering it right away. There was kind of an awkward silence. And then she changed the subject.
The next day, I got home from school and being presented with a package of four textbooks about human development. It was anatomically correct, very scientific and straight to the point. She told me I could read the books and ask her any questions I wanted to - but it felt clear that the books were supposed to answer everything.