The proof that the little prince existed is that he laughed, and tha the was looking for a sheep. If anybody wants a sheep, that is a proof that he exists.

More from The Little Prince

• Children, I say plainly, "watch out for the baobabs!"
• Grown-ups never understand anything by themselves, and it is tiresome for children to be always and forever explaining things to them.
• I did not know what to say to him. I felt awkward and blundering. I did not know how I could reach him, where I could overtake him and go on hand in hand with him once more. It is such a secret place, the land of tears.
• I have lived a great deal among grown-ups. I have seen them intimately, close at hand. And that hasn’t much improved my opinion of them.
• It is only with the heart that one can see rightly; What is essential is invisible to the eye.
• What makes the desert beautiful is that somewhere it hides a well.