I have not been sleeping enough. I felt groggy and blamed it on getting less sunlight. It affected my habit of reading and focus.
Last night I was in bed by 9 pm, had good 9 hours of sleep, and I am feeling all charged up. After so many days, I was able to spend some time reading and thinking. My knee pain has also subsided. I will be going for a run tomorrow.
I am also noticing that my quality of sleep, dreams are correlated with what I am consuming as in movies, reading, news, etc.