Why do it? So I can become aware of my eternal self. The part of me that watches is not the part that will wither and die. 

The part that watches is eternal, and will forever exist. The watcher takes notice of the world rising and falling.
Having access to that formless realm is truly liberating. It frees you from bondage to form and identification with form. It is life in its undifferentiated state prior to its fragmentation into multiplicity. We may call it the Unmanifested, the invisible Source of all things, the Being within all beings. It is a realm of deep stillness and peace, but also of joy and intense aliveness. Whenever you are present, you become "transparent" to some extent to the light, the pure consciousness that emanates from this Source. You also realize that the light is not separate from who you are but constitutes your very essence. -Tolle