What was a fortune?

A memory flitted into my head as they do sometimes. A memory of a book I loved as a child but have never seen since, and, indeed, about which I can recall very little. The only thing I can remember is the character's name: Pookie.

So I did what I always do in these situations: ask Google. And this is what came up.

Pookie is a little white rabbit with wings. Unhappy with his lot - being different - he leaves home to seek his fortune.
"What was a Fortune? He had no idea, but he thought it must be a mixture of happiness, lettuce and kind words."

It was first published in 1945 so it's quite possible I had it as a child in the 50s but even now, having read about it and seen the illustrations, there are still no bells of recognition ringing. On Goodreads a lot of people say it was their favourite book from childhood so I think this must have been the one I 'remember', but something else keeps flashing into my head, not lingering long enough for me to grasp it.

So until I do let's say that Pookie is indeed the beloved book of my childhood. The research was worth it simply for that wonderful quote anyway.