I played similar games with my toys - had extensive families that had adventures - but nothing nearly so hardcore as this:
"My Ponies—which, by this point, filled most of my bedroom at any given time, since I would build them cities out of playsets combined with cardboard boxes that I had modified to suit my needs—began a multi-generational saga of false queens, royal espionage, forgotten princesses, kidnappings, murders, and a thousand other things that no one really wants to think about seven-year-old girls playing out in their spare time…and yet. Majesty (the Queen of the Ponies according to the official playline) ruled from the Dream Castle with an iron hoof, cruel and unforgiving, while Moondancer and her rebel army struggled to put the true heir, Powder, on the throne. Sometimes Ponies died, and would go into the box in the closet for a few months before they were repurposed with a new identity and a new role in the ongoing game."
Whoa. (Pun unintended but I will let it stand). Yeah, my childhood storylines about the baby of the family getting spirited away by a "bad actor" (never really quite an evil character) and having to be rescued by his or her older siblings were pretty tame by comparison. (Also, there were lots of simply-fun storylines: using cardboard boxes and the flexible "road tracks" from one of my brother's racecar sets to build an "amusement park" for them).
But yeah. I can remember that. The long afternoons spent making up stories and acting them out in my head.
I didn't become a writer. Or rather, the writing I do is very different from novels or short stories.
And I confess: I do still make up stories in my head when stuck waiting somewhere or something, but I can't do it with the facility and lack-of-embarrassment that I had when I was seven. (And that makes me a little sad).
Another observation, about the 1980s cartoon: "In the very first animated adventure of the Ponies, they fought the Devil. Like, the Devil. He wanted to transform innocent Ponies into dragons of darkness and use them to bring about eternal night, as one does."
Holy COW. I always dismissed the show - being a terribly, terribly sophisticated 12 or 13 year old when it came out - as a "half hour toy commercial" (probably parroting something I saw a talking head on PBS say). But, yeah - that's pretty hardcore, as are some of the old Pony comics that Heck Yeah, Pony Scans! puts up on her tumblr. (I don't know if the comics were just in the UK - where she is - or if the US had them too. Some of the storylines in her comics do have words or references a US child would not get)
And no, the Ponies I own now don't have "adventures." I have the little family groupings I've imagined up but everything is very tame - no false rulers and princesses in hiding, no Pony Resistance. (Perhaps it's because I'm sufficiently baffled and dismayed by things that go on geopolitically in the world as an adult. I could see a child inventing those kinds of stories, though - out of a desire for a sense of control over a world, or a desire for something more than the humdrum every day world of school and playtime, or, some kind of motivation similar to that which drove me, even as a happy child in a family that loved her, to wonder "What if I really am not an ordinary kid in an ordinary family, but a princess who has been hidden here to protect her from unrest in her country, and some day the old royal retainers will come and tell me who I really am, and take me away to be the ruler of a country?")