When I was young my teachers were the old.
I gave up fire for form till I was cold.
I suffered like a metal being cast.
I went to school to age to learn the past.
Now when I am old my teachers are the young.
What can't be molded must be cracked and sprung.
I strain at lessons fit to start a suture.
I got to school to youth to learn the future.
Although never so cracked as to experiment in the free verse preferred by many younger poets, Frost continued to experiment in verse into his eighties, writing witty epigraphs, one “Political Pastoral,” and two dramatic masques: A Masque of Reason and A Masque of Mercy. 
 Also, a possible allusion to Gerald Manley Hopkins' theory of “sprung verse,” a predecessor to what would become free verse.
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