The problem with the advice: 'expand your comfort zone' is that while it is useful advice for most people, I think it is overdone in certain subcultures. (mostly intelligent people in competitive business fields). Lots of people already live an uncomfortable, unhealthy life because of chasing money and success. I think being out of your comfort zone too much is an important contributor to burnout and sometimes even counterproductive as it might prevent you from becoming really good in the thing that you love. It is obvious that you need to mix the 2 behaviours: being in the flow (do what you love), and being out of comfort zone: The question is which audience needs encouragement for which? I am not sure that the HN audience needs much encouragement for expanding their comfort zone.