Despite being vaccinated, I contracted measles as an adult in late 1994. It was horrible. Terribly bad high fevers (had to sit in shower of cold water to cool down), hallucinations, no sleep for days on end, didn't eat for ~ 10 days. I was suicidal one day. Would not wish it on anyone.
I will always remember the first signs, I abandoned a summer game of golf after a few holes as I felt very ordinary so walked back to clubhouse to sit in the cool while my mates played on. The TV was on and it was the afternoon that Shane Warne got his test hat trick.
I deteriorated in the days following, visited several doctors (including one home visit on evening of NYE) and the hospital emergency (I was convulsing) but no one could work out what was going on until I presented to doctor #4 with the spots, all over my body including inside my mouth. He was an older guy and asked if he could show my symptoms to all the younger staff who had never seen it before, to which I agreed.
I suspect I picked it up during a visit to a local primary school in the week before, during an official visit program at the end of a long stressful and intense work period in a tropical climate and I was so completely knackered I was probably immune compromised.