Self-Awareness is very important.

Self - Awareness is very important. When you tell yourself  I shouldn't be thinking about this before I go to sleep, you are practicing Self-Awareness because you are monitoring your emotions and judging their potential impact.
When you practice Self-Awareness, you give yourself far greater control of your actions. This control gives you options. You can decide not to react to negative emotions. Instead you can develop a positive attitude that allows you to let go of the emotion. You can also channel the energy of the negative emotion into a positive action.
If you don't learn to control or rechannel a negative attitude, it can have a terrible impact on your life. It may have already happened. Do you become easily angered, impatient, insecure, or cynical for reasons you don't understand? Do other people tell you that you tend to overreact? Do you often find yourself wondering why you got so upset? So angry? So offended? It may be that you have an attitude that you need to examine and root out.