Started taking T via a gel/lotion and after about two weeks I noticed a significant change in my productivity. The rut/fog was gone, I was working like I did 15 years ago.
Prescription ran out, was out of town, basically missed 10 days. Fog was back, a week on it again and it is gone.
Moral of the story, don't try to "will" your way out - see a doc, make sure everything is working right.