The mental illness is when option B in this example seems preferable to small inconveniences and embarrassments, and when one doesn't think of things like, (C) forget about it and go hang out with some friends.
One has to work 9-5 whole life that slowly kills their health and die horribly. That's normal, but if one does not want to continue that, it's illness. One must suffer. There is no other way whatever people here says, the real world does not work in any other way.