This quote comes from Maxwell Maltz’s book The New Psycho-Cybernetics, an incredible read, especially when you consider that he wrote the original in 1960!
“The habit (of multi-tasking) is particularly insidious because it is seldom recognized for what it is. When we feel jittery, worried, or anxious in thinking of the great amount of work that lies before us, the jittery feelings are not caused by the work, but by our mental attitude, which is, ‘I ought to be able to do this all at once.’ We become nervous because we are trying to do the impossible, and thereby making futility and frustration inevitable. The truth is that we can only do one thing at a time. Realizing this, fully convincing ourselves of this simple and obvious truth, enables us to mentally stop trying to do the things that lie next and to concentrate all our awareness, all our responsiveness, on this one thing we are doing now. When we work with this attitude, we are relaxed, we are free from the feelings of hurry and anxiety, and we are able to concentrate and think at our best.” (Italics were in the original quote)
I would add the simple phrase: Be here now! Live in the present moment and my guess is you’ll be a lot more relaxed and calm…and you’ll actually get more done!