Duck in Tree

Yesterday a duck landed in a tree branch outside my window. I stared at him since I didn't believe ducks perched in trees, I thought they stuck strictly to water and land. But there the duck sat on the branch, though none too comfortably. His webbed feet had difficulty keeping steady.
I called some friends and asked, "Do ducks sit in trees?" One friend commented that since I had seen one the answer must be yes. Another asked if I had gotten enough sleep, while another suggested it was a dream.
What did I realize from this incident? You never know what you're going to see, or what may happen. And the same goes with writing. You may know where you're going and what's going to happen, when all of a sudden a character or plot takes a completely different turn. Of course, a character doesn't suddenly land in a tree... wait a minute, I do believe that happened in one of my witch books.
See, you never know!