Many parents don't want children. Yet I've never met anyone who wanted to give his child back.
God is smarter than we are.
Sadly, I don't agree with you. I know a few parents who don't say that they want to "give their child back", but they behave like their children are a nuisance, and I would guess that if they had it to do all over again they wouldn't have had children at all.
You really think anyone would admit if they did?
Sadly, several years ago Anne Landers (or Dear Abby, I don't remember which) did a poll and asked that question: "If you had it to do all over again, would you have children?"
Majority said, no, they would not.