I think this is why doctors consider chronic pain kind of not a thing. We are supposed to recalibrate. But I'm personally pretty sure this is nonsense and they have convinced themselves this is true so they don't have to feel bad about withholding powerful painkillers due to society disapproving of them.
This sounds pretty fanciful and ungrounded. In general doctors don't "consider chronic pain kind of not a thing". I have chronic pain, I see doctors about it, and none have ever expressed any doubt. Quite the opposite: some of the doctors are chronic pain specialists. There are pain management centres at hospitals to help people with it, and they prescribe "powerful painkillers" if they're useful, but they often just aren't (e.g. for me).
We are constantly in pain, it’s just that we have calibrated our brains to ignore specific levels of pain or cut off completely sensors.
Typical example of signal we filter out is the sense of our organs moving inside our body.