Understanding Pretty

I had a friend say to me recently "You think you're pretty, but you don't understand that you are." That thought really hit me. My whole life, parents have told me that I was beautiful. Of course I didn't believe them, because people my own age never thought so. When I was kissed for the first time, I was in high school. By then it had been a very long time since I'd thought I was pretty. For years after that first kiss I believed that I was average looking, and that I was lucky that certain people were attracted to me. Then I went through some serious self evaluation, and I realized that I could never be happy if I didn't love myself. So I went through a lot of work to believe a lot of positive things about myself.
Still, my physical appearance is the thing that I have the hardest time with. Believing that I am attractive has been and still is one of the biggest barriers that I face on my journey to true self love. I'm pretty. I get that now. I struggle with trying not to be conceited and also trying to be proud of how I look. But I can look at pictures of myself and look in the mirror and think "I'm attractive." I tell myself this over and over again, because I think a part of me just wants it to be true, and saying it enough will make it so. I work on looking good, to a certain extent, and I know that I don't look as good as a lot of other people do. I'm okay with that.
I don't understand that I'm pretty. I don't inherently believe that I am a desirable and attractive person. The evidence in my life just doesn't show that to me. But I do think that I'm pretty, I think that there are reasons why certain people may be attracted to me, and I can get certain things in life that pretty people can get.
The distinction my friend made may seem small, but it hit me like a truck. I had to sit there for a moment, not saying anything, and really digest that. Is it easy for people to see? That I don't understand my own attractiveness? I've seen it in books, people that don't get the extent of how attractive they are. I just never thought that I was one of those people.
Does this change how I see myself? Not really. I don't know if I'll ever understand that I'm pretty, I may have missed that opportunity in my life. It just makes me think about how I'm perceived. Do people see me as more attractive than I see myself? Does that change anything?
In some ways, I think it's sad. Because I see people that don't understand their own attractiveness. They battle with self esteem, just like I do, but they shouldn't, at least not in the physical looks department.
I'd like to say that I don't place a lot of importance on my looks. But I'm a nineteen year old girl, and I was brought up in a society where that mattered. I've always had really attractive friends, I still do, and so in comparing myself to them I never thought of myself as attractive. Now that I'm starting to, things feel different. Am I attractive? I don't know. I don't understand the few people that are attracted to me. But at least now I do think I'm pretty. If I think it hard enough, perhaps one day I'll believe it.

"Everything has beauty, but not everyone sees it." -Confucius