Going Downhill Fast

One butterfly spies a glint in his eye; The birds sing as he cycles by Oh, why should he feel sad? This world ain't so bad And besides - Woe betide he who would frown When natural beauty abounds And now, with wheels spinning free He's picking up speed... Two butterflies tie knots in his stomach - They love it when he goes too fast! The wind whistles past In vast oceans of air that will mess up his hair Though he no longer cares anymore for Over-indulgence in vanity's Vacuous vice Just once or twice, thrice Four times in five we forget we're alive And neglect to remind ourselves Wait, then, for me Oh great Mercury! As late as you may be Will you wait for me? Three butterflies realise when it's time to depart - They have tickled his ribs, they have fluttered his heart But the starting is easy compared to the stop And the bottom is hard when compared to the top