In my opinion, the steps represent time. They represent the idea that there are times in the past that are now all gone and can never be found again. Even though they are gone, however, we can still recall what was important in those times.
The steps have changed from wood to granite over time. In just this way, time passes and the things that happen to us change. But this is not really all that important. Time and the situations it brings change around us, but the important things (our memories of love and things like that) remain with us always.
The “old wooden steps” are a predominating image in the poem. They represent “a time past” of memories when life was new and love was ardent. That the steps have been “replaced with granite” indicates a loss of the good memories. The granite in the steps makes for a solid stairway, but it has none of the past associations. From the poem’s context, we are also to infer that granite suggests the granite of a gravestone. The speaker ends up denying recollecting any other sounds because she concentrated so much on her husband’s “cheerful, unafraid, youthful, ‘I love you too,’” in response to her statement of love (line 7).
harry said he didnt kill voldemort, i dont believe him