A central theme of Clive Barker's The Thief of Always is that having too much curiosity for selfish reasons is bad.
He was stuck in the imaginary world because Harvey asked many questions about the house and when he got to know he wasn't able to go out of the imaginary world he was shocked because Karna would eat him if he stepped into the wall of mist/exit.
He was stuck in the imaginary world because Harvey was told not to ask many questions but he still asked many questions was curious about the house and was selfish. When he got to know all the truth about this house it caused Harvey not to be able to go out of the house, and if he did Karna with eat him alive if he touched the wall of mist. In the middle of the book, Harvey doesn’t listen to those warned and gets into the trap of Karna. This shows that too much curiosity and selfishness can be a painful or unpleasant outcome. If Harvey listened to those who told him not to ask any questions Harvey wouldn't have been struggling to get out. Therefore too much curiosity can lead you to a painful or unpleasant outcome. Harvey asks questions that are not selfish and tries to save the people in the holiday house. The good thing caused the reward because when Harvey enters and stays a day in the holiday house,32 years pass by. After Harvey returns from the holiday house he starts asking questions to himself to solve the problem in the holiday house. This makes Harvey save the people in the house still stuck there. In return, Harvey was gifted by getting his 32 years. This shows that too much curiosity can be a painful or unpleasant outcome. Harvey saved everyone from the holiday house because he asked the right type of questions. If Harvey hadn’t asked the right questions, he wouldn’t have saved the people in the holiday house and the people wouldn't have been grateful. Therefore too much curiosity and selfishness can lead you to painful or unpleasant outcomes. A central theme of The Thief of Always by Clive Barker is that curiosity and selfishness can be a painful or unpleasant outcome.