When the artist has exhausted his materials, when the fancy no longer paints, when thoughts are no longer apprehended and books are a weariness, - he has always the resource to live.
From The American Scholar by Ralph Waldo Emerson
In other words, "writer's block." Even when a professional creator, the process can become tedious. It is even more difficult to be inspired when the work is by its nature a bore.
Most of my waking hours are in front of a computer. Hour after hour of interaction with information - chosen or imposed. Taking a break of fifteen minutes, or if I'm lucky, forty-five of them, brings ideas and enthusiasm. Without fail.
Being instead of performing.