A simple translation of the Upanishad containing the original text in Devanagari, transliteration of each shloka, and word-for-word English rendering followed by a running translation and notes based on Shankaracharya's commentary.
As soon as I think that I am a little body, I want to preserve it, to protect it, to keep it nice, at the expense of other bodies; then you and I become separate.
-Swami Vivekananda