Imagine that everyone in the world has a bizarre relationship with the truth and sleep. Everything they believe while asleep is false, whereas everything they believe while awake is true.
Consider Sting and Fiona.
Sting believes that Fiona believes that Sting is asleep.
Fiona believes that Sting is asleep.
Is Sting awake or asleep?
Is Fiona awake or asleep?