Q. I have incurable, inoperable back pain that severely hinders my ability to sit and necessitates my taking a cushion wherever I go. Many, I believe, view this as a sartorial eccentricity. I have two issues: how can I politely — or even humorously — deter people I meet from probing my medical history and offering their own treatment advice (‘Have you tried Pilates?’ ‘You must meet my cranial osteopath!’)? Conversely, a close friend recently dismissed my condition as akin to his bone-idle, sponging girlfriend’s ‘leg problem’ (‘It’s ethereal and comes and goes’).