While I like reading MMM, I also really dislike the way he uses numbers. What bothers me is that he pretty much always does his computations based on averages.

While I like reading MMM, I also really dislike the way he uses numbers. What bothers me is that he pretty much always does his computations based on averages. This lets him do math on things that aren't really comparable, like the risks of driving and the benefits of exercise. Riding a bicycle is great, I do it myself because it's frugal and pleasant to do. But I don't think these benefits are as quantifiable as MMM implies.