In the Samyutta Nikaya 56.41 we encounter a very strange story called the Lokacintā sutta. In this sutta a man relates how he went off and sat down by a lotus pond to reflect on the nature of the world. Sitting there he saw a very strange thing or vision. The result was that he thought that he must be going mad, must be insane. Read the sutta if you want to know what he thought he saw. He returned to the city and told his friends about his vision and they too concluded that he was mad. However the Buddha stated that he was not mad and that what he had seen was real. However the Buddha went on to point out that this kind of “reflection’ is quite fruitless and useless in the famous concluding remarks to the sutta.