Well, it's a though question for me to answer since I had myself plastic surgery ten years ago.(nose job).
I think you can do it if something really bothers you.
It's no about what people think about you , it has to do with your own image.
I mean, I was really disturbed by my nose, and I wad hidding behind my hair!!!(sounds stupid, doesn't it?).
Since I had surgery (I was 20 years old when I did it), I feel better about myself and I guess it helped me in some way. An d I would do it all over again.
But I' wouldn't have my face lift or something like that (sorry for my bad english, I'm french).