I had it first in 2012: it gradually came on, initially eased by a change in my thyroid prescription, then I had to stop work completely for 5 months. I could still potter about, shop or meet friends for an hour but was supported well at home. One day I suddenly felt better and got back to work after a month. The same happened in 2015/16 but it started with a cold that wouldn't shift. Back to work after 8 months after another seemingly miraculous 'feel better' day. Have now been fortunate enough to stop working and was enjoying a great summer when suddenly cfs pounced again. Looking back I can see there were warning signs over 3 weeks or so. Would love to hear if anyone else has had the SUDDENLY BETTER experience. I have had CBT which is useful for optimism, and help with pacing. Am about to seriously investigate the Optimal Health Clinic in London.