I remember asking science teachers about how it is that trees can grow without depleting soil level around them? I even had one teacher suggest I was stupid an

I remember asking science teachers about how it is that trees can grow without depleting soil level around them? I even had one teacher suggest I was stupid and this question was ridiculous. 'What do you mean?' I insisted there was some discrepancy. 'Trees grow out of the ground, everyone knows that.' Only later I realized photosynthesis accounts for most of the tree's mass. Later I read in Feynman's Surely you're Joking... and he brought up this question as well. Felt like a vindication.