When I am . . . traveling in a carriage, or walking after a good meal, or during the night when I cannot sleep; it is on such occasions that ideas flow best and most abundantly.
Source: From an Internet collection of quotations.
-- Wolfgang Amadeus Mozart, (Jan 27 1756-1791), Austrian composer; He was child prodigy who composed 600+ works - chamber music, symphonies and operas, e.g., The Magic Flute, 1787.