I think I was a staged onset, and I think the main culprit was EMF/RF--not a popular trigger, but Martin Pall has pointed at it, and I think he is right--of course there are other triggers but I think this is an underestimated one. I drove with a friend from Montreal, my home for over 50 years, to Victoria BC in August 2006. I arrived in the best of health (73 years old) with my beautiful kayak, a good bike, my beloved Concept 2 rowing machine, prepared to explore much of BC by bike and kayak (had already done some kayaking there, and now my daughter and the kids were there). Moved into an apt building topped by a forest of cell and other antennae. For the fist months all was well--walked and biked around the town... and then in December an odd pain and high BP triggered by a walk--Emerg, no heart attack, sent home. But felt not quite right, and late January a more intense version hit me, Emerg again-no problem found--but there followed a few ghastly months--no-one could find anything wrong, but I could not do anything, and kept getting hit by high BP spells etc. Somehow regained most of my energy over the summer, well enough to go back to Montreal for Xmas with friends, but came back to find myself wiped out, and have had no "remissions" since, though there have been fluctuations.
Took me two years to figure out what was happening, rented a Stetzer RF meter, and found sky-high readings in my power outlets--plugged them full of Stetzer filters, and that improved things a bit; a couple of years later moved to another apt, improved a bit, but not much, and now of course the building has WiFi installed--I was not consulted, "smart" meters too--I am lucky enough to live two stories above them. My symptoms are mainly lack of energy, PEM, OI and stuff like that--not much to show on the myalgia, immune or even cognitive (though some there--fatigue hits there too) fronts--Julia Newton has a small paper some years ago proposing that when ME hits the old their chief symptoms are fatigue and OI. Fits me! So as a result I fit into the CCD, but not the Fukuda definition. And I am male, so all in all a bit of an outlier. But there was an interesting recent paper from Norway I think showing the sexual slanting of ME only began around puberty, and ended a while after menopause. Seems ME is a pretty equal employer of the young and the old.