The Whole World Was Created Only For My Sake
The Gemara says that a person should say to himself, "The whole world was created only for my sake." This thought has far reaching implications. When you realize that the whole world was created for no one but you, it follows that you are the only person in the entire world, and that the survival or destruction of the world hinges on your choice to do good or evil. Since you are the only one around, you need not be concerned about the opinions of others when you are serving G-d, for next to you, all else is of secondary importance. When you look at life from this perspective then you will serve G-d with total devotion, without any ulterior motive or muddled thinking. You will then break down all the klippos - the outer barriers that prevent you from perceiving holiness.
(Degel Machaneh Ephraim)