Being a wizard, of course, would mean that Gandalf would know exactly when to look ahead and when to look back, and not get tangled up doing too much of the one or the other. A life lesson for all of us?
“Where did you go to, if I may ask?” said Thorin to Gandalf as they rode along. “To look ahead,” said he. “And what brought you back in the nick of time?” “Looking behind,” said he.
Source: JRR Tolkien, The Hobbit (London: HarperCollins, 1995), p. 41