Meter and rhyme both help with memory. Modern poetry is often more free verse, and though that opens up a lot of possibilities, it does often make the poems harder to remember.
alliteration
the spear
Emily Dickinson made a lot of poems in the past. She made 105 poems.
Late 2008 early 2009 if I could remember
He who?
Back when very few people knew how to read, balladeers and troubadours would travel around, passing on the traditions and history of the world through poems and songs. The use of repetition and rhythm made it easier to remember the songs (some of which were enormous, like Beowulf). The tradition stuck: repetition is used to emphasize the song's theme, and makes is easier to remember the song. For those who prefer to listen to the music rather than the lyrics, repeating various points of the song gives cohesion to the song.
Odysseus
It made travel easier and fasterIt provided safer travelAnd it made more money for the creators :)
"Little Old Letter" by Langston Hughes was first published in 1956 in his collection of poems called "Selected Poems of Langston Hughes."
The affect it had on early humans was that at one point they had to make the tools on their own and then they then formed a group which made it easier to the tools and they said they had time to come back and hunt the animals to get the fur and bones to make the swords and weapons.
Banks made it easy for businesses to borrow money.
If you are asking about Robin Hood the story dates back to 1225 when stories were told as long poems. People couldn't read, so stories were told as oral poems. This made them easy to remember and as time went on the story changed and characters added.