I've been thinking about this thread.
I don't think it's about 'not caring' how I look - I do care, and I take care with my appearance, I just care less what others might think. Again, I don't not care, but I care less.
I am me, with good features, middling ones that I don't mind, and, well, less fortunate bits
I agree with a PP who said it may be related to even when I was growing up that my looks were never a particular priority, I was praised for other achievements, school, sports, music, friends were important, fashion, make-up, trends much less so (to the point that I am quite useless at makeup: a bit of eye liner and mascara is the height of going-out make-up for me...).
I agree, parents putting their children down by being nasty about any aspect of how they look are being abusive. Any of you who are finding their own brand of confidence and happiness with their looks after abuse are resilient, strong survivors 