Why did Truman's first girlfriend help him?

The Truman Show is a film produced by Paramount Pictures in 1998. Directed by peter weir and starring Jim Carrey, laura linney, noah emmerich and Ed Harris. The film was released in the United States on June 1998. This film tells the story that Truman is the hero of a popular soap opera. Everything around him is fake. His relatives and friends are all actors, but he knows nothing about it. Finally, Truman walked out of this virtual world at all costs.

Truman grew up in a small town called Taoyuan Island (actually a huge studio). He is the agent of an insurance company in this small town. Truman seems to live the same life as ordinary people, but he doesn't know that there are thousands of cameras pointing at him every second of his life, and the whole world is watching him all the time. He doesn't know that everyone around him, including his wife and friends, is an actor in The Truman Show.