So he wrapped his bedclothes around the clay image.

In the morning he was found dead, but his idea was saved, and other hands gave it enduring form in marble.
"I do not know how it is with others when speaking on an important question," said Henry Clay; "but on such occasions I seem to be unconscious of the external world.

Wholly engrossed by the subject before me, I lose all sense of personal identity, of time, or of surrounding objects." "A bank never becomes very successful," says a noted financier, "until it gets a president who takes it to bed with him." Enthusiasm gives the otherwise dry and uninteresting subject or occupation a new meaning.
As the young lover has finer sense and more acute vision and sees in the object of his affections a hundred virtues and charms invisible to all other eyes, so a man permeated with enthusiasm has his power of perception heightened and his vision magnified until he sees beauty and charms others cannot discern which compensate for drudgery, privations, hardships, and even persecution.

Dickens says he was haunted, possessed, spirit-driven by the plots and characters in his stories which would not let him sleep or rest until he had committed them to paper.

On one sketch he shut himself up for a month, and when he came out he looked as haggard as a murderer.