Mediocrity is a worthwhile tactic if you're not optimizing for money or status, but, say, happiness. Ambition can cause a lot of pain, particularly in feelings that you have not lived up to your potential (I've seen plenty of that happening).<p>YC readers are understandably strongly biased against such values of take-it-easy life. I don't subscribe to such values either, but they can not be straightforwardly discounted as inferior just like that. I would argue that understanding your limitations is just as important as developing your abilities.