From R. S. Thomas's "To a Young Poet":

    For the first twenty years you are still growing,
    Bodily, that is; as a poet, of course,
    You are not born yet. It's the next ten
    You cut your teeth on to emerge smirking
    For your brash courtship of the muse.
    You will take seriously those first affairs
    With young poems, but no attachments
    Formed then but come to shame you,
    When love has changed to a grave service
    Of a cold queen.