What is the gist of the poem 'A Slumber did my spirit seal '?

“A Slumber did my Spirit Seal” by William Wordsworth tells of a speaker’s realisation that his beloved is not immune to the ravages of time.  The theme of this poem is related to the death of a near one. There is pain in the beginning but at a later stage this pain turns into peace and calmness. This is because of the thinking that the loved one is now one with nature and is far from the earthy pains and feelings. The poem begins with the speaker describing how up until now his “spirit” had been sealed off. His mind and soul had been protected from the realisation that his love, Lucy, was going to be subject to ageing, just like everyone else. As he never actively acknowledged this fact he lived without “human fears.” His lack of fear made him unprepared for the shock of reality when his love died. 

It had seemed to him, while she was still alive, and his spirit was in that trance-like state, that Lucy could not “feel / The touch of earthly years.” Time could not affect her as it does everyone else. This illusion was shattered. The second stanza of the poem speaks of this realisation. His love now has “no motion” or force to move through the world with. Additionally, time and death have taken her sight and hearing from her. Ageing has done to her what it does to every other living thing and she has become a true part of the earth. Just as the “rocks, and and stones, and trees” change with time, so now, the speaker sees, does Lucy.
Regards