No, I didn’t hate my childhood
Some parents might worry that the reason you don’t want to have children is that you didn’t like your childhood. They might fear that you have negative associations with the way they raised you, so you don’t want to put those experiences on somebody else. They can even fear that you not having kids is your way of saying you didn’t think they were good parents, so you don’t have good role models, and/or fear you’d become them. You can shut this down right away and tell them all the reasons you adored your childhood and that your parents were wonderful. This isn’t about them.