This is the story of my husband. When he was young, his father brought home a parrot. At first the parrot was in a cage but later on, a foot was tied with a rope so it wouldn't fly away. The situation was like that for many months. The parrot was fully oriented in the house and the kids were just waiting for it to talk. In one occasion, their father took off the rope from the foot of the parrot so the bird can be free inside the house. And it did roam around. But it didn't last long before the parrot took flight.
That is a neat lesson not to judge a bird by its demeanor. As what my grandfather used to say, birds have wings for flying so do not forget that it can fly. This reminds me of our pigeon that also left us by flying away just like that.