"Tintern Abbey" and Time

I find it interesting that “Lyrical Ballads” beings with "The Rime of the Ancyent Marinere" and ends with "Lines written a few miles about Tintern Abbey". Both are incredibly long poems. "Rime" is fantastical and supernatural, while "Tintern Abbey" seems to be based on an experience of Wordsworth. They are distinctly works of their respective writers. Despite the collaborative bond, and the fact that Wordsworth contributed to the premise, I don’t think Wordsworth could have written “Rime”. His mind seemed too rooted in the natural world to delve that far into the supernatural. These poems are the opposite poles of Romantic poetry; but, I get the same feeling from both poems. I don't think Wordsworth necessarily intended this, yet at the end of the poem I am struck by melancholy. The speaker has accepted the changes in his life and the landscape over the years, and is even glad for some of them. However, even embracing change does not lighten the realization that youth has gone and only death and separation lie ahead. Long after the speaker is gone and eventually forgotten, change will still come to his landscape. His memories have been left hanging in the air, but below them the river will turn and the green recede. Sometimes I find myself wanting my memories to hang in the space where I created them, so I can return to the place/person/time unchanged and unaffected by the future events that have transpired between then and now and then. I think this is related to a universal rumination of choices made and the never-ending desire to be able to undo mistakes. Perhaps with the Singularity and other technological progress (like that time machine someone must be building) this will be realized. If we did have the ability to leave everything as we remembered, waiting for our return, would it be worth it? Is stagnation really more comforting than change?