You have your most intense / realistic dreams during REM sleep which is deep sleep.
What would happen if you were put into cryo / suspended animation for a long time? In such a deep sleep would your dreams eventually become indistinguishable from reality?
Wouldn't it be crazy if we're were all on a ship right now sleeping? Our AI helpers decided to screw us over and created a world for themselves in our dreams to dominate. Those would be the "elites" of the world.
Imagine HAL from 2001 a Space Odyssey watching over us as we went into suspended animation and then he turns on us at some point while we are sleeping. How would that play out?