The deluding power of Maya called illusion is discussed extensively in our holy texts such as Puranas.  It is said that the effects of illusion linger to a certain extent even after the attainment of the Knowledge.  Suppose a man dreams of a tiger.  When he wakes up, the dream no longer exists, but his heart continues to palpitate.  To illustrate the power of illusion Sri Ramakrishna used to narrate the following story:

Some thieves came to a field.  A figure made of straw resembling a man had been placed there to frighten the intruders. One night a party of thieves was approaching the field to steal grains.  When they came sufficiently near they saw the figure and were scared.  They could not muster enough courage to enter the field.  One of them however was bold and he approached the figure and found that it was made of straw.  He came back to assure his companions that there was nothing to be afraid of.  But, still they refused to go.  They said that their hearts were beating fast.  Then the daring thief brought the figure made of straw from the field, threw it on the ground and said, “It’s nothing, it’s nothing”.  Then only the illusion in the minds of the other thieves was destroyed.

Sri Ramakrishna would explain that Maya through its power of illusion deludes man.  Caught in its meshes, man suffers endlessly.  He loses his way and deviates from his pursuit of the true goal of life.  He finds it impossible to get rid of illusion, since his efforts are lukewarm and sporadic. Sri Ramakrishna would add that by denying it repeatedly through the process of ‘Neti, Neti’ i.e. ‘Not this, Not this’ one can ultimately get rid of it and proceed towards true knowledge.