A shepherd, counting his sheep one day, discovered that a number of them were missing. Much irritated, he very loudly and boastfully declared that he would catch the thief and punish him as he deserved. The shepherd suspected a wolf of the deed and so set out toward a rocky region among the hills, where there were caves infested by wolves. But before starting out he made a vow to jupiter that if he would help him find the thief he would offer a fat calf as a sacrifice. The shepherd searched a long time without finding any wolves, but just as he was passing near a large cave on the mountain side, a huge lion stalked out, carrying a sheep. In great terror the shepherd fell on his knees. "Alas, o jupiter, man does not know what he asks! to find the thief I offered to sacrifice a fat calf. now I promise you a full-grown bull, if you but make the thief go away!" 
We are often not so eager for what we seek, after we have found it. Do not foolishly ask for things that would bring ruin if they were granted. 