If a bird is raised in a cage, does it resent it's lack of freedom? Probably not. Most likely it would not know what it was missing. It might have an undefined longing in it's heart, but it would not truly understand it.
But later... If it was somehow freed as an adult; and then tried to fly and found it's flight muscles were weak, that it had not learned to fly as a young bird and was now struggling to learn as an adult what most birds learn while adolescents, then it might feel anger and resentment. Both at those who had kept it in a cage, at the cage itself, and at herself too. For all those wasted days spent cheerfully singing in a cage, instead of learning to fly.
