everyone is 'pretty' but in thier own way. make-up is a lie showing people you are who you aren't. like Dr.Suess once said, "Be who you are say what you feel because those that matter don't mind and those that mind don't matter." so it doesn't matter if you're 'pretty' or not because every one is, just not in the same way.
I don't think that it's something that anyone can explain to you; you have to find it inside yourself. Ask yourself, 'what makes me beautiful?' and list three things every morning that you amor about yourself.
Lol, just like yourself. No matter if you think you've accomplished your goal of being as "pretty" as you want to be, there is ALWAYS going to be that one judgemental jerk that doesn't like the way you look. Instead of trying to look at what other people define as "pretty", find your way on your own. It's far better than anyone else could come up with. :)