The moon, on the other hand, is a poor place for flags. Ours looked stiff and awkward, trying to float on the breeze that does not blow. It is traditional, of course, for explorers to plant the flag, but it struck us, as we watched with awe and admiration and pride, that our two fellows were universal men, not national men, and should have been equipped accordingly. Like every great river and every great sea, the moon belongs to none and belongs to all. It still holds the key to madness, still controls the tides that lap on shores everywhere, still guards the lovers that kiss in every land under no banner but the sky.
Revision entails making structural changes.
Drafting is usually a process of discovering an idea or argument. Your argument will not become clearer if you only tinker with individual sentences. Successful revision involves bringing the strongest ideas to the front of the essay, reordering the main points, cutting irrelevant sections, adding implications. It also involves making the argument's structure visible by strengthening topic sentences and transitions. Revision takes time.