system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do plot twists work? How do authors hide it from us and why can't we "unsee" it afterwards?
gpt
A good plot twists hides the important things in the details. E.g. on the first day the narrator walks a trail and takes 10 mins, the next day they start walking when the bell strikes 3, then barely made it in time at the end of the trail to a 3:30 tea party. The author could make some spectacle at the tea party to distract you from the time. They've hidden the fact that the narrator must have done something in that 20 mins in the story without drawing your attention. Once you know what happens in the 20 mins,  that 20 mins will stick out like a sore thumb because now you know to look for it.

A bad plot twist just comes out from nowhere and is a deus ex machina.