I actually am not sure that women who stop taking care of themselves are doing so out of an overabundance of self confidence. I think it's often because of depression or apathy, fatigue etc. Laziness can come into it, complacency etc. But I don't know many women who have "let themselves go" and lounge around in dirty ripped sweatpants eating Cheetos because they think they look amazing just as they are. If you love yourself you take care of yourself.