Your identity is built upon a string of memories and their associated emotions. You carry this identity with you like a passport and everything that you experience in your life checks itself off against this passport. It is your face to the world. You use it to define yourself to yourself, to define yourself within society. Your attachment to this definition of yourself is so great, that you will destroy yourself before you will change your idea of who and what you are.
The process of enlightenment is the annihilation of this passport, the annihilation of your personal identity. It destroys all links that you have to yourself. It destroys all links that you have to the world. This why it has been said that enlightenment is a calamity; yet this fear of enlightenment is irrational and only arises from the extreme attachment that you have to the lists of qualities on your passport.