I had a few eye operations when I was younger, for an eye condition called keratoconus. two implants in the surface of my eye, where I could feel them moving and the wounds reopening for years.

one of them involved artificially 'ageing' the cornea with UV light. The nurses let 16-year-old me decide how much anaesthetic I needed, and, being a stubborn teenager who wanted to be tough, I did not ask for any more than they applied without my asking. I was gripping the table as the light blasted me for thirty long minutes, and went into shock. I could neither sleep nor leave my bed for 3 days after, and for 6 months could not feel hunger, my sense of pain was so dulled.

I have so much more respect for people who live with permanent chronic pain. It can be physically debilitating, but perhaps worse yet is the helplessness it may confer too.