Any person with minimum common sense or no prank experience would have run away ages ago, but to the people of Aduseon who had experienced all kinds of pranks, this was nothing.
Some people did run away though, and when their neighbours made fun of them when they were grabbing their essentials, they said, "If this is the princess's prank, then all that would happen was that I was tricked. I could come back without much damage. But if somethings really happening in the castle, then I'd be safe."
This theory made some people convinced to run away too, while it made some people only laugh harder.
The people who were slightly paranoid ran away when the first scream occurred, and those who were cautious ran away after the series of screams rang out.
The ones who stayed back though could be seen as foolish or courageous, completely depending on a person's view point.