Once every five hundred years or so, a summary statement about poetry comes along that we can't imagine ourselves living without.
A. R. Ammons
Other quotes by A. R. Ammons
I can't tell you where a poem comes from, what it is, or what it is for: nor can any other man. The reason I can't tell you is that the purpose of a poem is to go past telling, to be recognised by burning.
Even if you walk exactly the same route each time - as with a sonnet - the events along the route cannot be imagined to be the same from day to day, as the poet's health, sight, his anticipations, moods, fears, thoughts cannot be the same.