Imagine a group of birds has been bred and raised in a cage for centuries. The cage is the only ‘reality’ they know. To them it appears ‘natural’. Of course you and I know better because we are aware that the natural environment for a bird is in the wild.
The birds don’t know that though. Of course, as you or I can imagine the unnatural environment of the cage causes all sorts of problems that simply don’t appear in nature. Behavioral issues due to the confinement and other problems are attributed by the birds to be just a reflection of the shortcomings of ‘bird nature’.
To us it seems comical, and we can clearly see the issues are due to the unnatural cage environment in which they are living. But, being the only environment they have experienced, they simply aren’t equipped to see things as we see them from outside the cage, with a different perspective.