The poem “My Heart Leaps Up” is about a rainbow, but it is also about childhood, reminding us to enjoy simple pleasures. We all remember the joy we had seeing rainbows when we were young. As we grow older, we need to find ways to recapture that magic.
The speaker still enjoys rainbows, and they make his heart leap.
So be it when I shall grow old,
Or let me die! (lines 5-6)
He doesn’t want to every forget to enjoy things as he did when he was a child. You have to stop and take in life’s simple pleasures.
The Child is father of the Man;
And I could wish my days to be
Bound each to each by natural piety. (lines 7-9)
The speaker wants to remind us that we are still the children we were when we are adults, and we are still bound to each other and to our childhood selves.