Ego Loss
A lot of people will not experience this in their lives, but it is a good feeling for most people. It happens to people when they take Mushrooms or Acid and look in a mirror for too long, but it can also happen regularly.
Ego Loss is when you realize that it doesn't matter what your hair looks like, or what clothes you are wearing, or what Sun glasses you have on, or even how old you are. Because there is something constant. Even though your body replaces all of its cells every 7 years, and even though you may start too feel older, there is always a constant.
This is ego loss. And usually it also comes with a feeling that there is something much bigger than yourself.