I write down on paper how I feel, the work I do, exercise, food I take, everything. That means if one day I am not ok I can rewind and find the culprit very fa

I write down on paper how I feel, the work I do, exercise, food I take, everything. That means if one day I am not ok I can rewind and find the culprit very fast, like getting exhausted from doing too hard work the day before. In your case, you will be simply forgetting what you did once you sleep. Or you could be simply ill. I usually think very clearly and fast. Usually my mind is never foggy unless when I am ill, like an occasional headache(once in a year) or when I get the flu. I do not drink coffee nor significant alcohol. Those can make you bog down. My mind was boggy when I started working from home in front of a computer years ago. I realized I just needed exercise every day.