1. Joined too many activities 

High school is already such an adjustment period so don't put so much pressure on yourself to join more than two activities. More than two can cause you to become stressed out and may make your grades fall.

2. Cared about what people thought of me

Too many times did I catch myself caring about how others perceive me. It really doesn't matter how others see you. As long as you love what you see in the mirror.

3. Let others choices define what I did

For example, one of my friends wanted to join the art club I would just follow right behind. Don't do that, do things that you enjoy doing. Now if you genuinely like art then do it but only if that will make you happy. Make a name for yourself.

4. Choosing to not focus on my grades 

Many times I chose to sit around and not actually do homework or study for a test then the next day go into the test not prepared. Then be surprised when I discovered I didn't get the grade I wanted. If you put work in you will get things in return. Even if you don't believe that grades are important it feels nice to know that something you did paid off.

5. Not allowing my true personality shine

This goes hand in hand with caring about what people thought of me. I had hidden my true personality thinking that people would find me weird or annoying and chose to act like someone I was not. Not only was I extremely unhappy but it made my mental and physical health go downhill. Be true to yourself and if someone doesn't like it then they aren't meant to be in your life. You are an awesome person and don't let someone tell you any differently.