Often I start a day very normally, and it goes normal till the time I interact with people. Once I do, it becomes confused, I forget what I wanted to do, I forget what I wanted to work on, and it mostly happens at the office and affects office work.
This lack of attention and preoccupied brain is a big distraction for me towards concentration at work. Then I try to find a solution towards this problem and in doing so I get frustrated as to what the optimal solution can be.
Sometimes we just need to set ourselves free and work, even if it is a bit slow. I have learnt this thing to some extent that even if I stay preoccpied, or have some strong stuff running inside my head, I keep pushing myself towards work, no matter how slow I work... It is helpful.