Evolution. When we lived in caves, there were men who were perfect estimators and there were men who were hopeless optimists. When the optimists said "I'm goi

Evolution. When we lived in caves, there were men who were perfect estimators and there were men who were hopeless optimists. When the optimists said "I'm going to get a deer!", the perfect estimators would explain with great precision and accuracy how difficult it was. The optimists ignored them, and the perfect estimators just sat around the cave. The optimists did finally catch the deer, even though it was probably more work than it was worth. That's why most of our ancestors were hopeless optimists. The perfect estimators just didn't reproduce. So how can we help but be hopeless optimists ourselves when it comes to generating schedules? The solution: multiply your schedule estimate by pi to get a round number.