'Ask to Embla, XIII'

They say that women change: 'tis so: but you
Are ever-constant in your changefulness,
Like that still thread of falling river, one
From source to last embrace in the still pool
Ever-renewed and ever-moving on
From first to last a myriad water-drops
And you -- I love you for it -- are the force
That moves and holds the form.

 	-- A. S. Byatt