Sometimes when we are too comfortable there is this feeling of missing out of something. Our body tells us we are weak when we are comfortable, then we start thinking of goals to achieve.
Most of the times we find peace of mind when we are uncomfortable, chasing our goals, pursuing our dreams. Something is always tell us to never stop, there is more to acheieve, more height to climb.
True peace of mind is when our body, soul and spirit are in alignment, and each of them have their own required. You can't be comfortable when you have not fulfilled all the requirements, one part must be troubling you, either your body, soul or your spirit.
Never give up, keep pushing.