A childhood belief about general

When I was really young I thought the food you ate just dropped down into your body and would slowly pile up starting at your feet. This theory was confirmed I thought when I was at the hospital once and had a chest x-ray done. The doctor was showing the image to my dad and I and my dad was pointing out my lungs to me. The bottom of the x-ray was really dark so I pointed to it and said "and that's the food I ate?" My dad goes "ya", probably cause he didn't know what I was talking about. I struggled with the problem of what happens when you fill up your whole body for awhile until I learned about digestive systems in school.