Brain fog and its many guises

There are a few CFS topics that I have wanted to write about for some time and brain fog is one of these. Brain fog, described as "a state of confusion or lack of clarity" [1], is a symptom suffered by many people diagnosed with CFS. It is something that I too have experienced regularly over the last 11 months. For me, however, brain fog is more than the inability to think because of a muddled head. I have had a range of symptoms relating to my cognitive abilities, each of which I associate with the term brain fog. Many of these are experienced by healthy people and I too had some of these before I became ill, but since I have been diagnosed I have noticed them happening more and more, especially when I am tired. I wondered if anyone else with or without CFS had suffered these scenarios. What are your thoughts on the subject? Here are a few of the things that i relate to brain fog:

1. When I read signs, adverts or newspaper billboards, the words that i read are often not the words printed, but words that look similar, relating to something that I have been recently thinking about. After a second look the real word comes to me.
   
2. A similar thing happens with people. Often, when I walk past people in the street, for the first few seconds I see a person that i recognise. Again, a second or closer look makes it obvious that the person is not who I am thinking and often looks nothing like that person. This has been happening a lot to me in Germany.
3. My memory for names has become apalling. I find that when I am introduced to someone their name never sticks in my head. This never used to happen.
4. Also, I don't really pay attention to what I'm doing. I often find myself asking - did I lock the door? Did I take my tablets?
5. Again, relating to attention, my concentration span is terrible. I cannot concentrate on anything for any length of time before my mind wanders off elsewhere.

My research is associated with memory and I know quite a lot about it. Indeed, I have even studied everyday memory lapses [2]. So, I know that these are all fairly common memory lapses and in themselves don't merit any worry. The point I want to emphasize is the frequency with which they now happen to me. I'd really like to hear other peoples' thoughts and experiences.

References:

1. http://www.drlwilson.com/articles/brain_fog.htm

2. Elsweiler, D., Ruthven, I., and Jones, C. "Towards Memory Supporting Personal Information Management Tools" Journal of the American Society for Information Science and Technology 2007 (pdf)