I don’t know,’ said Frodo. ‘It came to me then, as if I was making it up; but I may have heard it long ago. Certainly it reminds me very much of Bilbo in the last years, before he went away. He used often to say there was only one Road; that it was like a great river: its springs were at every doorstep, and every path was its tributary. “It’s a dangerous business, Frodo, going out of your door,” he used to say. “You step into the Road, and if you don’t keep your feet, there is no knowing where you might be swept off to. Do you realize that this is the very path that goes through Mirkwood, and that if you let it, it might take you to the Lonely Mountain or even further and to worse places?” He used to say that on the path outside the front door at Bag End, especially after he had been out for a long walk.

J.R.R. Tolkien