Worry.

Worry is thoughts, images and emotions of a negative nature in which mental attempts are made to avoid anticipated potential threats.
We all tend to worry over things. It may be from marks to friends. For me, I worry about many things. But the thing that I worry bout most is my future. All these nasty thoughts run through my head as i continue my day at school.

We have to remember not to worry about things and lift it up to God. It may be hard at first but, there's nothing you will regret afterwards.
After a sermon or Sunday school class, I tend to forget things. I often walk out like nothing has happened. I think that many of us listen to a sermon and it goes in and then out. We have to learn to meditate on God's word. Put his Word into action. Be the salt and light of the world. Practice His word by reviewing over and over again in your head.

The more time you spend reviewing what God has said, the more you will understand the “secrets” of this life that most people miss.

-Rick Warren.