I think GP was just making a point about the fact that “tired” is a subjective experience, like pain. Arguably, if you’re on pain medication, you’re not in pain, even if your body is sending pain signals that your brain just isn’t receiving or paying attention to.

Indeed. Pain is also interesting because chronic pain, AFAIK is sometimes a misfiring of pain signals even when nothing is physically wrong.

Turning off that misfiring with drugs would be dangerous (pain is an alert) but also improve the quality of life of so many people!