So I'm reading this great book at the moment, Tower of Bones by Connie Jasperson. The premise is that a young lad is the next in the line for a family of mages who uniquely combine abilities of battle-magic and healing-magic. He's been tucked away in one of the worlds in the book living on a farm until his Dad sends him out on a quest.
It's a great book that tugs the forelock to classic epic fantasy, such as The Belgeriad and the like. What got me pondering as i read it was the premise of the 'farm boy' setting out on an epic journey to save the day. I used a similar device in my own fantasy series, with Emelia being a servant rather than a farm-girl.
And trawling through my secret fantasy cupboard (cunningly disguised as a book-case) it is a popular theme. The aforementioned David Eddings in the Belgeriad tells the story of Garion, raised on Faldor's Farm, who discovers that he is an immortal sorcerer and wielder of the Orb of Aldur. The five Belgeriad books are his journey of discovery as he learns of his heritage, his family, falls in love (kind of) with a princess, and takes on the dark god, Torak. Better than mucking out pigs certainly.
Although Eddings was often criticised for writing very linear fantasy, he is astonishingly popular and I must say his books are very readable.
Around the same time Eddings wrote Belgeriad, Terry Brooks wrote the first Shannara trilogy. Repeatedly hammered for being a LOTR rip-off, it was none-the-less crazy popular. I recall loving these three books (in fact I found them in my garage the other day, original cover and yellowed pages an' all). In the book, Shea Ohmsford is taken on a quest to get ahold of the Sword which, as a half-elf descendant of Jerle Shannara, he's the only one who can wield it. Shea was tucked away in a nice spot called Shady Vale, adopted by the innkeeper, and fulfils my own personal fantasy of living in a pub, with his adopted brother, Flick. So not a farmboy, but a pot-boy.
Even the acclaimed and very very long fantasy Wheel of Time enjoys the humble beginnings characters--Perry the blacksmith's apprentice, and Mat the naughty farm boy. You dig deeper, and they're everywhere--Simon in Tad William's The Dragonbone Chair; Richard the wood-guide in Goodkind's Sword of Truth; Pug the kitchen-hand in Fiest's Magician; Ged/Sparrowhawk the goatherd in Le Guin's Earthsea. In fact we could go crazy and think of Luke Skywalker fiddling with droids in a sandy farm on Tattooine, or Harry Potter's humble beginnings as a resident of the Dursely's cupboard.
Given that it is such a popular plot device, there is clearly something in the idea of a humble beginnings character who goes onto save the day/ fulfil a prophecy/ become generally awesome.
First off is the 'everyman' idea. Here is the concept that authors write these characters because they allow the reader to empathise with the protagonist, that they permit the reader to become more personally involved with an often fantastical plot. The 'everyman' character allows us to transpose much of our own 'normal' identity onto the character and their progress.
Secondly, every decent fantasy character makes a personal and metaphysical journey as well as a physical one. Whether that's learning more about their hidden pasts, or more about life and love and so forth, a story has to involved change otherwise it generally has no purpose. And that holds true for non-fantasy as well as fantasy works.
Finally the character rising from humble farm-boy beginnings to greatness allows us to cast a similar analogous fantasy on our own lives. Who hasn't secretly harboured a desire to achieve greatness, or to find some hidden magic about our lives. And that is never truer than in fantasy works, where the farm-boy is often a covert saviour, a kind of 'messiah.'
So the farm-boy as a fantasy trope is likely to stay, after all... Sam Gamgee was a gardener, and even King Arthur was called Wart and hung around farms turning into animals.