06/10/2026
If your clearest thinking only shows up after nine at night, look at your calendar first.
You can test this with a pen. Write the letters A to J, then the numbers 1 to 10 and time yourself. Then do it again but alternate them: A1, B2, C3.
I tried it on camera. The two separate lines took me about 16 seconds and the alternating line took about 25. I was writing the same letters and the same numbers both times. The extra 9 seconds came from switching between them.
Lab studies find the same thing. People are slower right after they switch tasks and they tend to make more mistakes. If you know the switch is coming the cost shrinks but some of it stays.
Now look at a day of back-to-back meetings with messages in every gap. You are switching all day. By nine at night most of that has stopped, which may be part of why thinking feels easier then. Your body clock can play a part too.
If you fix your day and your focus still feels poor, see a doctor. Sleep, mood and other health problems can all affect focus.
This week, protect one hour before lunch. Close the door, turn off your phone and messages, then compare that hour with your evenings.
Source: Monsell S. Task switching. Trends in Cognitive Sciences. 2003;7(3):134-140.