It only went away, magically, with the evening launch at the Balloon Fiesta.
I can't begin to tell you how completely lovely I find the Bristol International Balloon Fiesta. It transforms Bristol completely. People form crowds all across the city, put out chairs in their front gardens, gather on the Downs in masses.
More than that, though, they look around themselves. They look into the sky. They smile at complete strangers on the street. They, quite literally, wander around with their heads in the clouds.
Maybe it's because it's so democratic -- everyone can see them, and they drift where the wind takes them. You don't need to buy a ticket, or to live in a posh area, or to support a particular team, or in fact to do anything at all.
If you don't join a crowd for the official launch times, you're still likely to be startled by the sound of a big gas burner a few hundred feet above your head. Then, when you look up, you might see a huge rainbow-coloured balloon, or a gently floating hammer, or even find yourself staring up the nozzle of a giant fire extinguisher.
Maybe it's simply that this mode of transport is so graceful, and so simple. Okay, balloon technology is quite clever these days, but fundamentally, what we're talking about is a bunch of people burning stuff to heat up some air, catch it in a bit of cloth, and use it to fly around the place. To fly. In a wicker basket, for chrissake. When I say it like that, it sounds like something out of a film with Dick Van Dyke.
And that's why I used the word "magically" earlier. This method of transport has the power to make strangers start nattering to each other, to fill fields with people from OAPs to their youngest great-grandchildren, all cooing and counting and just plain looking into the sky and marvelling at the pretty colours and the interesting shapes.
And, luckily for me today, it even cures headaches, apparently.
Now, I'm off to get some sleep. There's not much that can drag me out of the bed at five in the morning, but I'm setting my alarm for tomorrow. If it's raining, I'll stay in bed, but if the sky looks good, I'm off out to see if I can catch a morning launch.