I know, dude. Sometimes life isn't fair. I just want to be an ugly, fat, undesirable couch potato, but my narcissism and love of women and ice hockey make that impossible :( Woe is me.
Sarcasm aside, this is why narcissism is not always a bad thing. Deeply caring about the way you look provides excellent drive. As long as it's directed towards healthy methods of physical "improvement," you're going to be hard put for better sources of inspiration/motivation when it comes to exercise, eating right, self-preservation, etc. Oh, sure, you could say longevity, but we respond to what's right in front of us. I exercise and eat well because I want to look good today and better tomorrow. Long-term quality of life? That's icing. Or sprinkles. Or when you eat the cake and beneath that, there's more cake.