I used to write poetry fairly often in (my attempt at) the Old English alliterative metrical form. I read quite a lot about Sievers verses, and the rules for alliteration, the half stresses in the D and E verse types were for a long time a total swine, but I started to get the hang of it after a while
I wrote a poem in OE verse metre in actual honest-to-goodness Old English (probably replete with grammatical errors, alliterative errors, metrical errors and other sundry infelicities)
A few poets have dabbled with the Germanic metres. Tolkein of course, did his Lay of Sigurd in the metre. That came out a few years back. C.S lewis has a couple. W.H. Auden wrote Autumn in the Age of Anxiety, a long poem, entirely in germanic-esque verse forms.
And then there was George Johnston who occasionally did a poem in a Norse or OE metre.
I initially started writing poetry in OE verse metre because there are a thousand barriers to reading OE, one of them is, of course, the weird language, but the other is the metre. You read Dr. Seuss, or Byron and you know exactly how to read it and to slightly stress the rhyming word, but I, like any OE enthusiast have no prior experience, have not been brought up with rhythm so it's alien unlike a limerick. After a while I started to really get to like it, I would find myself watching telly and saying - hah! that was a D verse. In the end I found that though I really liked OE metre, I especially liked the Norse metres Drottkvaett and Hrynhenda. I wrote a couple of poems in Drottkvaett (fiendishly difficult).
RE mnemonic, I believe that AS England, along with much of the literate world was a transitional culture between oral and literate. Books back then were a little more expensive than they are today. It has been estimated that they would have cost the equivalent of what it would cost a modern european to buy a house. If you had a library, you were one of the vertiginously rich. When the printing press came along, the cost of books plummeted. Now you could own a book for a cost approximately equivalent to what we would shell out on a car.
I had read that The Venerable Bede was considered a prodigy because he could read silently without moving his lips !!!!!!!!