At that age, I'd take any excuse to make estimates and do minor arithmetic... I'd been hearing an ad campaign about smoking. I can't remember the details, but basically the ad said, every puff of a cigarette takes some number of minutes off of your life: I think it might have been two minutes per puff. At any rate, I decided to do the math for my grandmother. I estimated the number of cigarettes per days, estimated the number of puffs per cigarette and so on. When I was satisfied that I'd come up with a reasonable number, I poked my head into the front of the car, tapped my grandmother on the shoulder, and proudly proclaimed, "At two minutes per puff, you've taken nine years off your life!"
I have a vivid memory of what happened, and it was not what I expected. I expected to be applauded for my cleverness and arithmetic skills. "Jeff, you're so smart. You had to have made some tricky estimates, figure out the number of minutes in a year and do some division." That's not what happened. Instead, my grandmother burst into tears. I sat in the backseat and did not know what to do. While my grandmother sat crying, my grandfather, who had been driving in silence, pulled over onto the shoulder of the highway. He got out of the car and came around and opened my door and waited for me to follow. ... We stopped beside the trailer. My grandfather looked at me, and after a bit of silence, he gently and calmly said, "Jeff, one day you'll understand that it's harder to be kind than clever."
--Jeff Bezos, 2010 Princeton baccalaureate remarks, on the truly hard thing