You're afraid. That's why you can't leave.
5 seconds sound clip from the The Truman Show movie soundboard.
You can hear this line at 01:33:22.464 in the Blu-ray version of the movie.
Quote context
[...]
- You were real. That's what made you so good to watch.
- But in my world, you have nothing to fear.
- I know you better than you know yourself.
- You never had a camera in my head.
- You're afraid. That's why you can't leave.
- It's okay, Truman. I understand. I have been watching you your whole life.
- The episode when you lost your first tooth.
- With me.
[...]