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.
As a vessel is known by the sound, whether it be cracked or not; so men are proved, by their speeches, whether they be wise or foolish.
This is what I am. I have periods of enormous self-destructive depression, where I go completely off my trolley and lose all sight of reality and reason.