In Memori... um?

For years I had been remembering a non-existent line of poetry from Tennyson's In Memoriam. It struck me as being rather good, but then again I suppose non-existent lines of poetry that you remember often do.

O sorrow, live with me and be my friend. 

Along the way, I'd somehow managed to turn Tennyson's iambic quatrameter into an iambic pentameter - nice work if you can get it. Also, while googling around yesterday, I discovered that I'd made this non-existent lines of poetry from three unrelated lines:

O sorrow, wilt thou live with me - Tennyson, In Memoriam.

There was a man whom Sorrow called his friend - Yeats, The Sad Shepherd

Come live with me and be my love -  Marlowe, Passionate Shepherd to his Love

Remembering poetry is often like that with me. Poems I really love stick with me and I can quote parts of them years later, but the words change in my head so that, when I quote them to you, I might just be quoting something no-one has ever heard before. I've been quoting and requoting Yeats' An Irish Airman Foresees his Death, but I can't ever remember what adjective he uses in line eight.

No likely end could bring them loss
Or leave them luckier than before.

Or

No likely end could bring them loss
Or leave them happier than before.

Bartleby tells me it's the second version, but what would he know? He might be remembering the wrong word for the right line, too. Anyway, nowadays I find myself omitting whole couplets, or shifting around the order of the couplets inexplicably so the lovely climax

A lonely impulse of delight
Drove to this tumult in the clouds;

Might appear right at the start if I'm not careful.

Meanwhile, poems of my own that I've written, never bothered to print out, but remembered, seem to be constantly shifting around in my head so I'm not sure I trust myself with them anymore.

I'd give you more examples of non-existent lines that I can't remember, but that's just the problem. I can't remember what they are. Still, I suppose there is one consolation; the best example I could come up with is from Tennyson's In Memoriam, which is an excellent poem to remember non-existent lines from. No, no, I meant that as a compliment....!