Cognitive load includes thinking, planning, monitoring, anticipating, deciding, and regulating emotion. Much of that work is invisible, but it still uses real energy.
Invisible work still uses energy
Cognitive load is the mental effort involved in holding, sorting, remembering, planning, monitoring, and deciding. It is the work your brain does even when your body looks still.
This is why a person can feel exhausted after a day that does not look physically demanding. The effort was real; it just happened inside the system.
Modern life is full of open tabs
Unanswered messages, unfinished tasks, emotional tension, decisions waiting in the background, and things you are trying not to forget all take up space.
When too many tabs stay open, the brain has less capacity for patience, creativity, memory, and emotional regulation.
Externalise what you can
Write things down. Use lists that are short enough to believe. Put reminders somewhere reliable. Remove decisions that do not need to be remade every day.
The aim is not to optimise your whole life. It is to stop asking your mind to carry everything at once.