Growing mountains and trees

When we go outside, Samuel likes to collect twigs, branches, rocks and pretty much anything else he can find.  One day he found a toy flower with a long stem stuck in the bushes outside our apartment.  We washed it a few times and now he has a permanent flower.  I digress.  Yesterday as we were waiting for Joseph at the bus stop, he got some rocks and started putting them in ground.  He was explaining that "I planted the rocks so that it will grow a mountain when it rains."  He then planted sticks to grow trees in our yard.  I will have to explain to him tectonic processes that actually contribute to orogenesis, but for a little longer I will let him maintain his misconception.