So I had periodically heard about cluster headaches, and how they're supposedly "the most painful condition in medical science", but I never looked into it. Now, I had periodically had extremely severe headaches throughout my life. My parents had always told me that it was a result of pressure changes preceding and during thunderstorms, and I believed this because I had no reason to disbelieve it. These headaches were always focused behind one of my eyes, and made me extremely adverse to light. They were utterly agonizing, enough to effectively cripple me when they happened, and did not meaningfully respond to OTC painkillers. My eye feels kind of sore just remembering all of this.
Fastforward back to the present, and I'm reading the cluster headache article on Wikipedia. It sounds very familiar. The only major discrepancy is that there is no clear pattern of recurrence, nor do I specifically remember them happening in "clusters", as the name suggests. Rather, they would happen singularly every few weeks to months. I don't remember when the last one was, but it's been at least two years. Conversely, I can find nothing like what my parents described as the cause of the headaches.
So, I may or may not have the most painful medical condition known to science. If so, the upper limit of pain is actually kind of weaksauce. Horrible as it was, I just figured it would be more than that. While it made me want to curl up under my bed and die, I could force myself to do things if I had to.