In "God's Word for Today" Steve Oliver writes:

The answer, of course, is that they are. Visually, every person is the center of his own world. The problem is that we tend to forget that this is a sort of “optical illusion,” and we live and think as if we are, in fact, the most important person in our world. If we are not careful, our concerns can center on what is good for us; our worship can revolve around what we enjoy; even our prayers can boil down to requests for personal comfort. If this describes you, then in this passage Jesus called you to repentance — to turn away from self-centered living and begin living with God as the center, the controller, of your life.

Source: Christ, the Triumphant Lord: Adult Teacher's Insights, page 15.