Not to identify oneself with something, or to associate things with the 'me,' and to see that the idea that there is a 'me,' which is distinct from things, is a delusion.
When you drop the ego, you drop a whole world that you have created around it. For the first time you are able to see things as they are - not as you would like them to be. And when you are capable of knowing the facts of life, you become capable of knowing the truth. The facility of life is the first step towards truth. And ego is the most falsifying agent.