Technically, it’s not the actual list-making that’s so stellar for brain health—it’s isolating your tasks, from beginning to end, and physically (or mentally) checking them off. You see, the Sherzais are not huge fans of multitasking: “We say there’s no such thing as multitasking; it’s doing multiple things badly,” says Dean. Attention and cognitive decline are deeply intertwined (your attention naturally depletes as you age), and when you multitask, your attention becomes further compromised, which creates a perfect storm for cognitive decline.