Siddhartha realized that he was the Buddha, Awakened One, and that his life embraced the whole of the Universe. Out of this realization came the understanding of his life and its purpose. He understood the concept of oneness—that the life of the Buddha is one with all other lives to the extent that there is nothing to separate or to distinguish them. He came to embrace all lives with compassion, experiencing all joys and all sadness as if they were his own.
That the Buddha’s enlightenment allowed him to see the death and rebirth of all living beings according to their karma was further indication of the oneness of his life with that of others. The Buddha embraced all lives with his compassion and became one with them. He was able to recognize others’ joy as his joy and others’ sadness as his own sadness. In the Nirvana Sutra, the Buddha said that all living beings received different sufferings and that those sufferings were actually his own sufferings.