That was a question posed recently in a parenting group I've joined. I imagine that broadly, people would say things like "patience" or possibly "humility" (something I was thinking, the other day, upon learning that a couple expecting their first child had chosen a parenting manual they intended to follow exactly...as if children follow operating instructions).
But the first answer that popped into my head was actually literal. My 4-year-old is currently obsessed with how many letters are in different words. So I now know that "Philadelphia" and "Pennsylvania" both have 12 letters. I also know that 2 "Jasper"s make a "Philadelphia." These are definitely things that I never pondered before.
My children have, perhaps, tried to teach me patience in their often aggravating fashions. But I do know they have taught me a lot about time, and whether I am spending it on things that matter or not, and that you can do quite a bit in small bits of time. Someone was describing to me the other day that they need long, uninterrupted periods to write. My children have taught me that, at least for me, this is not the case.
What have your children taught you?