I visited Antwerp Zoo when I was 5 and I have one vivid memory of that
visit: Looking at a 15 square meter cage with a wolf in it. The wolf was
continuously running the same circle, down to the point that his path
was already centimetres deeper than the rest of the cage floor. I
remember that, minutes after I entered the zoo, I started crying. I hardly
knew what a wolf was, and neurotic behaviour was not something I would
possibly have been able to fathom, but I felt the unhappiness of that
animal.