Let me begin by saying that I am not talking about narcissism or self-absorption here. I am talking about your garden variety vanity. Frankly, I think it gets a bum wrap. Many of the things we do that will help us to live healthier, longer lives are really outgrowths of vain behavior.
For instance, say a woman is concerned about sun spots and wrinkles. She therefore uses a moisturizer with sunscreen in it, tries not to tan, and regularly visits the dermatologist. These behaviors will help prevent skin cancer and/or catch it in an early, preventable stage.
Another example would be that a man who is concerned about getting paunchy, so he watches what he eats and goes to the gym. These behaviors help reduce, among other things, high blood pressure and cholesterol, and the risk of developing type 2 diabetes.
I think we all need a little vanity in our lives. After all, if you don't care about how you look, well, then frankly, no one else will care about you either. Harsh, I know, but true.