When old age shall this generation waste,
Thou shalt remain, in midst of other woe
Than ours, a friend to man, to whom thou say'st,
Because us humans are not made of eternal stone or marble, we fall victim to this pesky thing called time. This generation (presumably Keats') will die due to old age, but the urn will not.
(The word “generation” can also be interpreted to mean both a measure of time and something created on a rather shallow level, perhaps less real than the urn because it perishes.)
Though the “woes”, or problems, of the old generation will be replaced by those of the new one, the urn will kindly stick around to be their historian as well, giving them some of the most immortal advice ever written…
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