...with thanks to Sheila Ryan for reminding me, and posting it today.
The secret of my incredible energy and efficiency in getting work done is a simple one. I have based it very deliberately on a well-known psychological principle and have refined it so that it is now almost too refined. I shall have to begin coarsening it up again pretty soon.
The psychological principle is this: anyone can do any amount of work, provided it isn't the work he is supposed to be doing at that moment.
From "How to Get Things Done." Robert Benchley.