Most people are like chained prisoners in a dark cave, to borrow Plato's allegory. All they can see is the wall in front of them. They cannot see even the fire that glows brightly behind, nor the actors holding the puppets that dance as shadows against the wall of the cave. For these prisoners, their entire world consists of these shadows on the wall.
One day one of the prisoners is released from the cave to the outside and at first he is blinded by the brilliance of the sun's light. Once his eyes adjust he is shocked by a full spectrum of colors that surround him in a reality that has more depth than he could ever have imagined, shattering his former concept of the world. When he returns to the cave he excitedly explains to the other prisoners that their shadow existence is all an illusion, that a richer, intensely luminous world exists just a few steps outside the cave. No matter how he tries to convince the others that their reality is but a pale fragment of what he had experienced, the other prisoners think he has gone mad.
There is a difference between the everyday appearance of the world we think we know, shaped by a consensus of everyday language and ideas, and the real world from which all things spring eternal. The real world cannot be discovered and experienced through observation or intellectual rationalizing. Another higher domain of reality lies behind the illusion of the shadows that we call the real world, and it can only be discovered and experienced through a quieting of the mind and directed attention to a level of awareness that opens the doors of perception and understanding to knowledge that is otherwise hidden behind the illusion of the day-to-day world.
Learn to quiet the mind, say the sages. See the world as it is, not as it appears to be when viewed through multiple layers of cultural conditioning.