For me, there is a massive difference between being content and being comfortable. When I am content, I am a being in a state of peaceful happiness. When I am comfortable, I am free from stress or tension.
When I am not exercising regularly, I am quite comfortable, but discontent.
When I am exercising regularly, I am content, but with periods of discomfort.
Living in a comfortable world does not work well for me in the long term. I need to be challenged, I need to be uncomfortable, I need daily discomfort.
Being content means finding the joy in each day, but there is also pain in each day.
I wake up early, I try to exercise daily, I write daily, I am working and in school part time, so I am not often comfortable. Usually, I am on the go, but I am content because my actions have purpose and my effort is building up toward a self-directed goal.
When I am comfortable, well, that is a different story entirely.
When I am comfortable, I am not challenging myself. I am not growing, I am not engaging with my environment, but rather, I am existing. I am probably snacking, feeding cravings as they come, rather than focusing on eating smart and what I know is right for my body. I am probably watching something mindless, which will not challenge or evolve my thoughts and assumptions about life, but rather, something mindless and time sucking.
There is absolutely nothing wrong with being comfortable, for an evening, day or two, maximum, but more than that and I am going to call it laziness.
You simply cannot reach your full potential when you are comfortable.