General Meaning . In this poem Charles Kingsley to talk about the disparity of youth and old age. There is a certain sentimental connotation to be further explored, of course, but the basis of the poem is refer in the differences.
Detail Meaning. Second, I really like the meter combined with the rhyme scheme. Without seeming too forced, the Iambic trimeter gives the sense that the "lad" has sat through this same speech before many-a-time, while the "every-other-line" rhyme scheme gives the monologue a lighter, more passive tone. The allusion to the simple natural order of things is compelling, and becomes truer the older one grows. The speaker uses the lad's presence to not only highlight the young beauty described in the first stanza, but to contrast that age described in the second.
Intention. Furthermore, the part of the elder pointing out of what things will be like when the lad grows up is another way of saying that all things will grow old one day!