Migraines are natures way of telling you a regular headache isn't so bad.
The doctor thinks the one I went through last night was probably triggered by withdrawing from prednisone, which I was taking for tendinitis in my elbow. (I think one of the signs that you're getting older is when one medical problem causes another one.) Stress and a lack of sleep can contribute to migraines, which pretty much explains the hours of agony, followed by several more hours of what felt a lot like recovering from a hangover.
I've only had four or five migraines in my life, so it was a memorable experience. And this afternoon I'm getting that heart scan, so -- another memorable experience.
Memorable experiences aren't what they're cracked up to be.