Once Sariputra and Zhuangzi have spent a night at a hotel.
Zhuangzi dreamed he was a butterfly, a happy butterfly flitting among blossom as it pleased. It didn't know that it was Zhuangzi. Suddenly he woke up and found himself, Zhuangzi. But he didn't know if he was Zhuangzi who had dreamed he was a butterfly, or a butterfly dreaming that it was Zhuangzi.
What Sariputra dreamed remains unknown because a true philosopher never shares his bedroom with a strange man.