Why can't you fully focus on the next task right after switching from another?

When you jump to a new task, part of your mind stays behind on the old one.

Sophie Leroy called it attention residue: when you switch from one task to another, a slice of your attention stays stuck on the task you just left, so you bring only a fraction of your focus to the new one. The effect is worse when the first task felt unfinished, and it can drag on your performance for several minutes after the switch.

You close a tense work email and open a report, but for the next ten minutes half your head is still drafting replies to that email.

Rapid task-switching means you rarely give the new task your full attention - the last task is still renting space in your head.

Finish or park a task on purpose before you start the next one, and you hand the new task a clean, full focus instead of leftovers.

Residue = the last task leaves a sticky film on your attention that the next task has to see through.

Learn the idea and practice English at the same time.