I've blogged before about how I used to want to have children, but then grew up to realize that I am in fact childfree.
Conventional wisdom is that people who are childfree may well change their minds (which is why it's so hard for those of us who have never had kids to get sterilized), but I find myself wondering if it might be the opposite.
Your worldview is first formed by your surroundings when you're a kid. You first think that your surroundings and experiences are baseline human reality, and then gradually your worldview broadens as you grow up and learn more.
And, when you're a kid, the primary adults in your life are, necessarily, adults who are raising children. So your very first impression of what you consider to be baseline human reality is that adults raise kids.
To arrive at the idea that you never want to have or raise kids, you have to put thought into the matter and question the basic assumptions you grew up with and conceptualize a reality that you may never have actually witnessed. Critical thought goes into it - it's not a decision made mindlessly.
Because of this, I wonder how many people who are childfree actually change their minds compared with those who previously wanted children and then changed their minds. This would be interesting to research.