Answer:
Filling a cup to the top.
Explanation:
In the poem “Birches” by Robert Frost, a man, probably the narrator looks at some bent birch trees and he's thinking about how they got bent. He imagines that the realistic conclusion is that ice storms bent them but he prefers the idea of a boy swinging on them which is something that he used to do as a child.
"He always kept his poise to the top branches climbing carefully with the same attention he would fill a cup up to the brim and even above the brim when he flung outward feet first with a flying kick, his way down through the air."
"One by one he subdued his father's trees by riding them down over and over again until he took the stiffness out of them."
At the end of the poem that the narrator seems to reevaluate his life...
The narrator chooses to see life through the “flexible” imagination of a child instead of adult “stiffness” and be a child again and just swing on birches for the rest of his life.
