For years I’ve been crying out in an increasingly frantic voice, “Multitasking is a myth! Multitasking is a myth!” Not because I knew something but just based on instinct — and the observation of my own deteriorating ability to focus as the number of devices I own increased.

Well boy howdy, if this isn’t the proof in the pudding I don’t know what is: “A study at the University of London found that participants who multitasked during cognitive tasks experienced IQ score declines that were similar to what they‚Äôd expect if they had smoked marijuana or stayed up all night.”

You heard it hear first: Go ahead and hit the town on a Tuesday night! Party on! At least you’ll be able to say you had a great time the next morning. With multitasking, you get the lower productivity at work and at home with none of the fun selfies and souvenirs.

(I believe this same principle applies at the group level: an organization that tries to be everything and everywhere ends up getting nothing much done. Mission focus matters.)

If you want to be your optimal self, find a way to break the multitasking habit (or, dare I say it, addiction). I’m not going to brag that I’ve completely broken the habit. It’s a daily struggle. But it’s a struggle that’s worth the time and effort.