If you want to get a ten year old to eat his cold cereal to the point the bowl is dry, then have his day begin with him having to rewrite his previous three days’ mistake-ridden writing assignments.
If you’re still unclear the meaning or origin of the popular, “You can’t have your cake and eat it too,” then you haven’t watched a seven month old eat with her hands. She grabs the wafer just fine. Her mouth opens. Her hand goes into her mouth. Her tongue touches the wafer. Then her hand and the wafer come back out. Boom. Unlikely as it seems, we now know that a baby’s hunger gave birth to the adult’s sad truth.