I, unfortunatelly, get them a lot, about 1 per day (not every day, of course!). At least they're not that strong.
Usually, it's either random or for being too much time on the computer or playing video games. Another reason for them is too much noise (that's why every time I go to a school field trip, I have to take 1 or 2 Tylenol packets with me.).
I rarely get migranes; but if I do, they're REALLY horrible (I even vomit when I have them :X ).