The great Taoist master Chuang Tzu once dreamt that he was a butterfly.
He fluttered between flowers, drinking the delicious nectar.
In the dream, he had no awareness of his individuality as a person. He was merely a butterfly.
Suddenly, he awoke and found himself laying there, a person once again.
He thought to himself — "was I before a man who dreamt about being a butterfly, or am I now a butterfly who dreams about being a man?"
One of my favorite from Zhuangzi!