I never ever think of myself as mentally I'll nor do I ever use that term to describe myself. When I am really bad but not aware of how bad I am my friends will sit me down and tell me that I'm sick right now...which I feel OK about them saying because it is more descriptive of what is really going on...as in I am experiencing symptoms of disease. When I am well I am not sick. I tend to lack awareness of the severity of my symptoms or behavior (even though I may have a basic understanding that I am not well), so I do not mind them reminding me using by saying I'm sick rather than mentally ill.