What is the deepest thing you’ve heard from a child?

This is a really interesting question!. The first thing that came to mind is this post by Andy Dent on Quora :

Trying to see if my daughter, maybe 4 or 5, was a pessimist or an optimist, I poured a half-glass of water and asked her “would you say that was half-full or half-empty?”.

Her response – “that depends if you’re drinking it or filling it”.

She is now grown up, teaching primary school and utterly adored by the kids she teaches.