What I can learn from my tween almost teen

My oldest daughter, Sophia, is not popular in the sense of what society considers popular, but she is sincere and friendly.  Last year, she even remarked that she is not a popular kid, not even close.  She stated that she is what they consider the lowest rung on the popularity ladder.  And while she talked about it, there was not even a hint of sadness in her voice but a smile on her face.  Status does not matter to her, but good friends who have the same hobbies and attitude as her is what she values.  I look at the variety of friends Sophia has and it is amazing!  She has her friends from Chorale and friends from school.  She has other friends from the church youth group and a good friend from her daycare days.  The interest of her friends also varies, some like to sing and act, while others are very good athletes, some prefer to watch a Harry Potter marathon while others prefer High School Musical.  I watch Sophia jump from one group of friends to another at school, never getting caught up in the drama.  If there is drama or a friend is upset with her, she moves on to another group until the argument is over.  As she has gotten older, I have yet to see her come home upset about what somebody has said about her.  Sophia is not the best athlete, but she continues to try sports - even when she comes in last, she still has a smile on her face.
So I am wondering, if my daughter - who is possibly going through the most challenging times in her life - can be so carefree, why can't I?  As adults we want what others have.  We need to be friends with the popular people to elevate our status.  Personally, I am always concerned about what others think about me.  Not only that, but I cannot stand to finish last.  After finishing the Boston Marathon last year, I was embarrassed with my time as I did not hit my goal.  I told my husband he was not allowed to tell anyone my time.  If they wanted to know they had to look it up.
I am thinking that if I start to live for me and stop trying to impress everybody else, life may become a little easier.  I might be able to enjoy life and not feel so stressed all the time.  I think it is humorous that I am learning this lesson from my teenage daughter!  Sophia, I hope that as you grow and mature you continue to live life for you, and know how proud we are for the light you shine into the lives of so many people!