Reddevil1968, Although I do not have CFS, I would like to tell you a bit of my own personal experiences. 3 years ago, I was in the similar mind set to yourself as I had never heard of the condition. I met someone online and we started to message each other. She had had severe ME for over 14 years, something I initially couldnt understand as she always seemed to be very bubbly and full of energy when I spoke to her. Even when I started doing some research I wasnt sure about it.
After a year of being in contact we met each other and ended up dating for a while. Not dating in the normal sense, rather I used to go up and we used to have dinner at home and then she went into a rest for a bit, then we spoke for about 30 mins, then back in a rest etc... It was not something I had ever experienced before. What people without the condition take for granted can be a great deal for an ME sufferer e.g. after she brushed her teeth, she felt exhausted and had to rest for 30 mins before being able to get dressed and then she would have to rest again as she would have used up all her energy getting dressed etc...
Anyway, quite often we would get carried away and talk for more then her allotted time and she seemed to be fine, oh boy was I wrong. The next day she would, as Avocado mentions, pay the price and would crash all day. Quite often she would try and do more than she could handle by going into adrenaline mode, paying for it after.
I have seen her when she has been in a bad way and I really do feel for her. Due to her bubbly-ness and wanting to do things that non sufferers take for granted, she always does more than she can physically do, so people may initially think she is fine but they do not see what happens after as a result.
She has had days where she can walk for 3 mins to her parents house and also days where she cant even get out of bed.
I have met a lot of people with ME in my own little crusade to see what I could do to help her. Not everyone is the same, not everyone has the same symptoms. It is a very complicated condition indeed. I would tend to agree with Avocado in the fact that trying to improve your fitness will not necessary help. I even met a poor little 13 year old who could not handle the sunlight and could only get out of bed for 1 hour a day so would spend the whole day in a dark room, how her parents cope, I do not know.
I came across a video which was produced by a mother and brother of a ME patient especially to help educate people as to the condition. It is an amazing documentry that may help you understand it a bit more. The film is called Voices from the Shadows and a link to the website is http://voicesfromtheshadowsfilm.co.uk
Please have a look at the film and it should give you more of a realistic insight into ME. It is free to watch online.
I used to be a sceptic when I first heard about ME but now, after a bit of research and my own experience with the ex, plus meeting other ME sufferers, I realise that it is not a nice condition to have and I would not wish it on my worst enemy.
Looks can be deceiving, smiley faces can hide a multitude of issues and its like the old saying, never judge a book by its cover.