Full Idea
Often after waking do you know that your dream was a dream. Still, there may be an even greater awakening after which you will know that this, too, was just a greater dream.
Gist of Idea
You know you were dreaming when you wake, but there might then be a greater awakening from that
Source
Zhuangzi (Chuang Tzu) (The Book of Chuang Tzu [c.329 BCE], 02), quoted by Bryan van Norden - Intro to Classical Chinese Philosophy 9.2
Book Reference
Norden,Bryan van: 'Intro to Classical Chinese Philosophy' [Hackett 2011], p.144
A Reaction
This is the key to the full horror of dream scepticism (as dramatised in the film 'The Matrix'). We can never know whether there is yet another awakening about to occur.