Under certain conditions, a person may mistake a rope for a snake. But what is actually perceived is a rope.
In his talks on Shankara’s Naishkarmya Siddhi (The Already Accomplished Self) Swami Dayananda says that the rope in this famous metaphor is called a substrate (adhistanam) and the snake is projected (adhyaropa) on it by a person who is momentarily confused.
It often happens that Vedanta inquirers assume that there are actually two things in reality, a substrate and a projection. It is like saying that beneath the snake is a rope. But seeing it this way is dualistic.
The right way to see it is to understand that the imaginary snake is displaced by the real rope. Similarly, Self knowledge displaces the world with the knowledge “I am seeing myself when I am seeing the world.”
If you don’t see it this way, you will believe that you have Self knowledge and a world of psychological problems. People think that Self-knowledge will help them solve worldly problems. “I will get from enlightenment what I have been unable to get from endarkenment.”
But there is no world to use for your own purposes. When you wake up from a good or a bad dream you don’t try to return to the dream to remove the suffering or re-experience the pleasure because you know very well that dreams are only your thoughts projected on the mind stuff. They don’t apply to the waking state.
Wise people understand that there is no world at all, only themselves. But if you read Chapter 2 of the Mandukya Upanishad which says “nothing is created or destroyed no one is bound or free and no one seeks or finds liberation” and yet keep on transacting with “the world” you haven’t understood. You should think that there is no relationship or that the experienced world is just a dream.