She's not like all the other people out there. She has no one but herself. She has many friends but she doesn't have that one bestfriend that would always stay by her side. Indeed, she gets sad about this.

Then she realized,
Maybe she is meant to be independent.
To depend on no one but only, herself.

And this realization has helped her build herself better. Now, she is ready to face and conquer every obstacle by herself.