Directing is a more pragmatic experience, where you have to deal with the restrictions of time and money that force you to make certain decisions you don't have to make when you're writing.
“Listen to the cry of a woman in labor at the hour of giving birth - look at the dying man's struggle at his last extremity, and then tell me whether something that begins and ends thus could be intended for enjoyment.”
“The countdown reached ten seconds and I could almost hear an invisible crescendo of stirring background music. 'Anchors aweigh!' Five, four, three, two, one... and we had ignition!”