But my point is that I do not think that I can reliably separate intensity from the other factors I mentioned in assigning a subjective number to pain.
An ice cream headache is certainly not the worst pain I have ever felt; I have never felt, for instance, that I might vomit if faint due to the pain of an ice cream headache. Nor do I think it is even the worst headache that I’ve had, though I’m not sure I am able to separate the quality and duration of the pain from its intensity, especially in this case.
The worst pain I have ever felt was slipping on stairs and landing with all of my weight on my coccyx. While I did not quite faint, I nearly did so. For what it’s worth, no ice cream headache has approached that pain.