To this day, I'm still not sure what triggered it, but I have a suspicion it might've been dehydration. I wasn't expecting it though. I drank a full camelbak's worth of water on the drive from Omaha, had a Scooter's coffee, and then probably 2-3 bottles of water before the symptoms had started. If I had had just the coffee or something I would've thought "yeah that checks out" but, to this day, I'm still surprised it happened... especially since I'd never had one before.As someone who has suffered from migraines as long as I can remember, I felt this.
Dehydration is a major trigger for me, I've come to learn. I don't know if that was your problem that day but that's the first thing I tell people. Drink lots of water.