Sometimes, I like to pretend that I can multitask. Except that I really can’t.

No one can. It’s not physiologically possible.

Certain repetitive, habitual type things, of course, can get done at the same time, like tying your shoes while carrying on a conversation. But two or more things that require focused attention simply can’t be done at once.

What happens, really, when we attempt to do two things at the same time, is that we handle them sequentially; our brains toggle between the tasks.

Some of us can toggle fast.

I’m a really fast toggler.

But there’s a huge cost to toggling.

There’s an energetic cost. It’s wearing to toggle. We end up feeling tired and overwhelmed when we’ve spent our day toggling.

There’s an acuity cost to toggling. It’s not possible to focus well when we’ve got a lot of balls in the air. We make mistakes when we toggle; sometimes catastrophic ones.

There’s a time cost to toggling. Studies show that it takes anywhere from 12 to 20 minutes to re-attend to a task once we’ve been distracted by another task. We’re actually less efficient when we toggle.

There’s a productivity cost to toggling. When we’re trying to do lots of stuff, few things get done to completion; and little gets done well. We’re actually accomplishing less when we toggle, not more.

There’s a human cost to toggling. Toggling causes us to be fragmented, distracted and superficial in our relationships. We fail to show up; we fail to be present; we fail to listen deeply. We dishonor our connection with one another when we toggle.

Toggling causes us to live in a state of continuous partial attention. Distracted. Stressed out. Spread thin. Mentally blurred.

“Deep thinking demands sustaining a focused mind,” Goleman writes in his bestseller Focus: The Hidden Driver of Excellence.

Peak performers know the power of focus; they harness the power of attention.

They do just one thing; the most important thing. And then they do the next thing. And the next.

If you want to be a peak performer – or if you only want to restore some sense of sanity to your life – stop multitasking.

It costs way too much.