When oversimplification complicates

How does an oversimplified explanation complicate that which it tries to explain?

I was sitting next to a mother and her young boy. The boy asked what a solar system is. I inched closer. I had to hear this. The mother balled up her palm indicating it represented the sun. She then took out a coin and moved it around her fist, indicating it was a planet and he should know there were several of this moving around the “sun.” The kid must have imagined the solar system as an angry hand running away from a lot of money! He must’ve concluded that the solar system is for all the hype he’s hearing about it from his young friends a shitty “system”.