But why do spirits walk the earth, and why do they come to me?"
"It is required of every man," the Ghost returned, "that the spirit within him should walk abroad among his fellow-men, and travel far and wide; and if that spirit goes not forth in life, it is condemned to do so after death. It is doomed to wander through the world--oh, woe is me!--and witness what it cannot share, but might have shared on earth, and turned to happiness!
...I cannot rest, I cannot stay, I cannot linger anywhere. My spirit never roved beyond the narrow limits of our money-changing hole; and weary journeys lie before me!

Charles Dickens