I personally suspect that the phrase was not invented by the type of people who use it today, but rather by someone recounting a remarkable rags-to-riches story, who chose a physically impossible analogy in order to emphasize how astonishing the success story was.
This happened to me the other night. Except I ALSO imagined that it was for sale on Amazon.com, and it had one-star reviews from people who were disappointed that it wasn’t actually upside-down as pictured in the listing.
I agree that children don’t automatically owe their parents anything, since they entered the “contract” without their consent and while extremely underage. But Abby and her mom are such identically stubborn jerkfaces, I’m sometimes surprised they don’t get along better.