From "Strong Enough? Thoughts from Thirty Years of Barbell Training" by Mark Rippetoe.

“To a very great extent, the health problems experienced by the members of the ridiculous culture in which we live are self-inflicted. They are the result of the reluctance of the bulk of the population to do anything that is either physically hard or something that they don’t want to do. People seem to have acquired the idea that they have the inalienable right to stroll through life without either having sweated, picked up anything heavy, worked hard, or eaten less than they wanted at every meal. This approach is, of course, wrong. And it has resulted in a lot of expensive, unattractive, and entirely preventable problems amongst people who seem puzzled about why things aren’t going well.
We have become lazy. I know you’ve heard this before, and I know it doesn’t necessarily apply to you or me the same way it does the general public. But I dare you to read Steven Pressfield’s Gates of Fire, his marvelous retelling of the Spartan’s battle with the Persians at Thermopylae, and tell me that you’re not a pussy.”