From
欧阳修's Song-dynasty prose
《醉翁亭记》 (Account of the Old Drunkard's Pavilion):
醉翁之意不在酒,
在乎山水之间也 - 'The old drunkard's heart is not in the wine, but among the mountains and waters.' Ouyang, demoted to Chuzhou, nicknamed himself
醉翁. Today almost always used in a pointedly cynical sense about hidden motives.