Originality

You know I have no motivation to write anything other than pony fanfiction, and never have? It's the oddest thing. Who knows, perhaps I could try my hoof at writing more professionally (pffffft "profesionally") one day but I don't have any intention. So why do ponies bring this out in me? It's the diference between a sandbox and a box of legos, actually.

Original pieces of writing are, as much as they can be, entirely from one person's head. You're working with a blank canvas, you're sculpting in your sandbox. There are certain limitations on what you can do, but just like you can either build a bucket-castle or those giant scupltures of sand, so to does skill determine what you'll create in your work. But there are tools there, and you need those tools. Archetypes, cliches, character models.... I can't imagine trying to just sit down and make up an entire world, populated with original and realistic people. Our minds are full of pop culture, for good or ill, so perhaps that's even harder today than it should be. It's hard not to default to things you know exist in other works or have heard about - more then once I've been caught borrowing ideas from other authors, either obviously or obliquely, and while on occasion I do this purposefully it happens just as often without my intention.

On the other hand, writing fanfiction is playing with a box of legos. You have a lot of different shaped pieces, and maybe even a couple models with pieces specifically designed for that model. But you can take everything apart and rearrange it, though rarely do your additions work better than the original. You can assemble things how you see fit, but if you're jamming pieces together then something has gone wrong. This is how I see it at least - I have, let's say, Fluttershy and Twilight, these two models, and I have these pieces that go with their sets, now how can I mix and match them? Some bits are ready-made and all you have to do is accentuate this or that, some things you have to build up nearly from scratch. Look at the models you're given and you can figure out how to make your Vinyl Scratch or your Bon Bon or whatever.

Because that's one thing I really enjoy. Especially in My Little Pony, you occasionally get these blank areas where you can fill it in as you please. Background characters and secondary characters. They're really almost OCs, but people tend not to write them as self-inserts and the reader is more willing to accept them as part of the world they expect. Of course our own "pop culture" comes into play in that you're likely to write a character as you've seen them written, especially one like Luna or Scratch, but it's still up to you and you have plenty of options. So it's really almost like writing original pieces, when you focus on background characters, and that's the funny thing. Of course what you do have is a world. Constructing worlds are hard, because there's a lot that needs to lay implicit, but still be worked out so you don't accidentally contradict yourself later. Worlds need to have mechanics that can't be explained so directly, like how the pegasus ponies control the weather in Equestria, and it all needs to fit some theme in a way - like how both the "tame" wildlife and controlled weather of Equestria fit to show both an idyllic land and ponykind's total dominion over their country. So BG characters in a preset world is really more of a starter set for writing original works - you can learn how to make interesting characters while already having a setting for them to explore and interact in.