system
A chat on subreddit /r/NoStupidQuestions
human
It blew my mind the day I learned trees grow from the air.  If trees grew from the ground we'd have a tree sized hole under the tree.
gpt
Humans do the reverse, to a degree - when you lose weight, a lot of it is lost to the air you exhale rather than, what you might intuitively suspect, to the toilet.