Being yourself
This means make your own decisions. Don't base every choice you make on what others think. Don't change your look, talk, body, etc., just be "cool". Staying true to yourself is to always keep your personality. Everyone is unique. For example, a young girl has three friends, each friend has decided that they all are going to sneak makeup to school. The young girl, who doesn't like makeup, agrees but she really doesn't want to. This is an example of somebody changing herself for somebody else.
Another example, once again, a 13 year old girl likes wearing her hair in a pony tail, wearing jeans, and t-shirts. Her "friends" tell her that her clothes are ugly. This girl changes her look so she can fit in with her friends.
These are both examples of somebody changing themselves. They will become less confident with who they are and they will eventually become lost in themselves. This is why you want to stay who you are and be true to yourself!