Philologists tell us her name is derived from the Indo-European root mna, found in e-grade as Latin mens (cf English mental,) zero-grade in Greek mnemosyne (cf. amnesia, mnemonic,) and a postulated o-grade (IE or early Greek? the sources I've seen aren't clear) montya, which became Mousa. The root seems to mean "mental activity," including both thinking and remembering. The Greeks highlighted her as memory by calling her (or them -- she wavers between singularity and multiplicity) the daughter(s) of Mnemosyne, or Memory personified as a goddess. Her connection with memory is of fundamental importance though often neglected. Homer as a performing poet worked from memory, so in invoking her at the beginning of his poems, he was asking not only for inspiration but for the bolstering of his powers of recall. And of course, what the epic poet is doing is preserving heroic deeds for the memory of the tribe. But surely there's more to it than this. One use of poetry in a pre-literate or early-literate society is that it makes it easier to remember things: it's easier to memorize a poem than a piece of ordinary language (I mean at least in the context of cultures where poetry was always in strict form.) The techniques of poetry -- regular meter, alliteration, rhyme, etc. -- are mnemonic devices. Consider the common American phrase for remembering which way to turn a screw, "Lefty loosey, righty-tighty," which uses the poetic techniques of rhyme and alliteration. Or innumerable proverbs: "Red sky at night, sailor's delight, red sky at morning, sailor take warning." If something's worth remembering, you'd better make a poem out of it. I think that one of the major obstacles to our understanding early ancient Greek poets' conception of their art is that we can't get rid of the decadent Hellenistic prettification of the Muses into wall-calendar art motifs. For earlier poets (this is not something I can or care to prove,) the Muse was a religious power as real and as powerful as the Holy Spirit was to a medieval Christian devotional poet. When Homer asked the sanction of the Muse for his art, or Sappho forbid mourning for her because tears should have no place in a house that is a temple of the Muse, they were not engaging in literary artifice, and to the extent we've been conditioned to assume that they were, we're barred from their consciousness.