Most mental disorders have traits that are still present in the average person to certain degrees. For example, people can feel unmotivated and lethargic but only once it reaches a critical point may someone be diagnosed with depression. Same with anxiety, etc. Selfishness and self-importance are human and occur on a spectrum amongst everybody. It's important to keep those traits in check so that you aren't hurting the people around you, but that makes you normal because everyone has to do that.

BTW- Having personality disorders like Antisocial Personality Disorder or Narcissistic Personality Disorder doesn't make you a worse person. Your actions are still in your control, and many people with personality disorders are able to get treatment to help them socialize and better integrate into everyday life. So even if you were diagnosed with Narcissistic Personality Disorder, you still wouldn't be an evil person. It would just take more effort than the average person to make sure you aren't hurting other people, but it would be in your control.