What, if anything, do children owe their parents?

This may seem like a debatable topic, but let me just quote answers from this wonderful Quora Q&A that I generally agree with:

Children do not owe anything to their parents, purely by virtue of the relationship of parenthood.

Any adult, who believes a child becomes indebted due to the act of raising that child, is ill-prepared to raise children. That parent will end up with a child who is resentful of the parent.

Nothing from parenthood itself. People choose to become parents because they want to be parents, and not in an effort to do the kids a favor. […] But of course parents deserve the same courtesy as every other human being: if they treat you well, they deserve to be treated well.