Many years ago when we used to rescue birds, I took a poorly budgie to the vet.
I took the cover off the cage to find the budgie spinning round and round on the perch, looking decidedly fit and healthy.
The vet said, "Are you absolutely sure you've brought the right budgie?" (we had about a hundred at that time).
The vet was right - I'd picked up the wrong bird. What a twit. :o(