I have a theory about why we often don't like our own pics. My face isn't symmetrical, so when I see me in the mirror, that is what I am used to. When I see me in a pic, it's the opposite way round, and to me, I look very lopsided. I would like to be able to turn my own pics around so that I see the same image as in the mirror.
Of course, all that discounts the double chin and grey hair!