Found this marvellous description from the poet Mary Oliver of how easy it is to be distracted as a writer:
It is a silver morning like any other. I am at my desk. Then the phone rings, or someone raps at the door. I am deep in the machinery of my wits. Reluctantly I rise, I answer the phone or I open the door. And the thought which I had in hand, or almost in hand, is gone. Creative work needs solitude. It needs concentration, without interruptions. It needs the whole sky to fly in, and no eye watching until it comes to that certainty which it aspires to, but does not necessarily have at once. Privacy, then. A place apart — to pace, to chew pencils, to scribble and erase and scribble again.
But just as often, if not more often, the interruption comes not from another but from the self itself, or some other self within the self, that whistles and pounds upon the door panels and tosses itself, splashing, into the pond of meditation. And what does it have to say? That you must phone the dentist, that you are out of mustard, that your uncle Stanley’s birthday is two weeks hence. You react, of course. Then you return to your work, only to find that the imps of idea have fled back into the mist.