I've been through a lot of ups and downs. I've been on both sides of it all, I guess. So there's not one specific event or thought that I'm dealing with or drawing from necessarily.
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.