Back in the 1970s, California had a senator, S.I. Hayakawa. The senator had young son, and one evening, he was drawing a bath for his son. When the tub was full, the senator put his sun in tub. But as soon as he did so, his sons screamed, Dad, make it warmer! The Senator, suspecting that, if anything, that tub water was too hot, reached down and felt the water. It was indeed too-hot. yet his son was screaming for him to make it warmer. But make-it-warmer means add hot water. So what's going on here? Question your assumptions. I think I know what makeit warmer means, but I could be wrong. Fortunately, the senator questioned his assumptions, when his sons said makeIt warmer, he meant make It closer to the state I call warm. To a young kid, there were temperatures of cold, warm, and hot. Make it warmer meant move the temperature closer to warm. Fortunately, Senator Hayakawa realized this and turned on the cold water. Back when my daughters were that age, if they'd said, Dad, make it warm I wouldn't have thought about it. It would have cranked up the hot water, My problem is that I would have not stopped to question my assumptions. I just would've gone along with the seemingly reasonable assumption that make it warmer meant to add hot water. Questioning our assumptions is vital to remaining open-minded. Let me give you another example. When I was seven years old, I on a family vacation driving up the coast of California. And I think I was being a particularly obnoxious seven-year-old. I probably was pestering my dad with questions. And my Dad took out a piece of paper and he drew the image on the screen. Two rectangles on top of three rectangules. My Dad told me that he would give me $100 if I could draw a single line that went through every line segment once and only once. $ 100 to any seven year old is a lot of money. But I checked the inflation since I was seven years old, and that would be over $650 today. All I had to do was to draw one line through each line segment. I could start inside or outside the rectangles. So I tried for hours to get it right. And when I have a solution, like the one on the screen, I'd hand it to my dad. and then I'd try some more. And I had my dad another solution. He'd say, you went through a line twice. I tried for the entire drive up the coast. We got to a campground that night, and I try by flashlight. For the next 12 years, any time I have a spare few minutes or was bored anywhere, I remember trying in the margins of my notes during high school classes. I remember sitting in the waiting room at a doctor appointment. For 12 years, I tried to solve this problem. It wasn't until sophomore year of college and a lecture on graph theory that I even began to question my assumption that there was a solution. Some of you by now will have recognized this as a variation on the famous seven bridges of Konigsberg problem that Leonhard Euler proved has no solution. But because the problem had been given to me by my loving father, I assumed it could be solved. When we fail to question our assumptions, we can stubbornly repeat our mistakes over and over, and, over. For 12 years, I failed to question my assumptions. Question your assumptions because you know what? Your assumptions could be wrong. There are really two things that make assumptions so dangerous. Confirmation bias and hindsight bias.