The 4-Hour Chef: The Simple Path to Cooking Like a Pro, Learning Anything, and Living the Good Life

by Timothy Ferriss

What we really need to do, to design, is look at the extremes. The weakest, or the person with arthritis, or the athlete, or the strongest, the fastest person, because if we understand what the extremes are, the middle will take care of itself.” In other words, the extremes inform the mean, but not vice versa.