This topic is not necessarily related to sleep and/or lucid dreaming (although in some ways it may possibly be connected). I would like to know if anyone here knows some techniques to prevent slow thinking while awake. I would also like to know if anyone on this forum has experienced the phenomenon that I often experience. It often feels like my cognitive abilities, mental processing speed, and even intelligence fluctuate on a daily basis. On some days I process information very quickly, and am able to solve complex problems very efficiently with almost no effort. On other days, my thoughts seem to slow greatly and my brain is in a fog. This phenomenon has no correlation with the amount of sleep that I get on the previous day, or any other noticeable life circumstances; it is apparently random. The only cure that I have found for it is to consume copious amounts of caffeine. Is there any way to prevent this "brain fog" phenomenon and does anyone have an idea as to what may be the underlying cause, because I cannot determine it. I do not have sleep apnea, do not drink alcohol or consume any drugs.