The ego is not the self. When one limits the ‘I’ to physical entity, it is called ego. The ego, body and world appear together and disappear together. Therefore, limiting the ‘I’ to the physical entity is creates the ignorance of the truth/reality. To understand “What is truth” and “What is untruth” one has to know the fact that; whether the mind/’I’ is within the body, or body and world are within the ‘I’/mind to get Self-realization.