Okay, so.. I have a theory, and a few pieces of proof leading me to believe Pinkie is actually smarter than she seems / acts.
Possibly A LOT smarter, in fact. Or at least, she COULD be if she wanted to.

Long story short, I believe Pinkie might have a so-called Eidetic Memory. (also called "photographic memory).

To put it simply - She remembers everything she sees, hears and reads.
For example - She remembers EVERY single pony in Ponyville and knows them all by name, AND remembers their birthdays and ages.
Ponyville is in fact bigger than it seems, we're only being shown a few specific locations and ponies. But when seen from afar,
it's a whole small town, not just a tiny village. They even refer to it as a town when speaking about it, which means that,
at a bare minimum, there are several hundred ponies living there - and Pinkie claims to know every single one.

However - one charactersistic of eidetic memory is to be extremely good at remembering ONE thing,
but in return be horribly BAD at something else. In Pinkies case, she's GOOD at remembering ponies' names, birthdays etc.
but she's NOT good at remembering their likes and dislikes, which is why she has the detailed information lists in her Party Cave.

Now, at some points she also seems to recall books and specific pages in books she has read or seen even if a long time has passed.

Which leads me to believe her "Eideticy" might also include a good memory for written words.
Meaning, once she has read it, she remembers it.

So, if she were to seriously start reading any and all books she could get her hoofs on (like Twilight does),
She could theoretically become the second smartest pony in Ponyville, only rivaled by Twilight herself.

Twilight might in fact ALSO have an Eidetic memory, making her capable of remembering almost everything she reads,
and making her extremely adept at stuff like organization and list-making (as proven in various episodes).

This theory is NOT completed though, it's just something I realized while I was lying awake at night due to my insomnia..

My insomnia is the cause of MANY awaken night, So I have a lot of other theories as well, some of which I might share here.

I know this theory is far from perfect, and there is probably proof both for and against it.. so tell me what you guys think.
Do you agree that Pinkie could have an eidetic memory, or is it just a bunch of coincidents and plain luck?

4660153

I have a theory that the show comes from a tiny camera that follows ponies around, and Pinkie is the only pony who knows about it. At least in their universe. :p In our universe, it's a cartoon, in theirs, it's a reality show of sorts.

4660156 Sounds interesting. I'd love to hear more on that theory, if you're planning on posting it. Or if you already have,
could you link it?

4660153 I see....
it's a good one, I like it

4660307

I have a feeling this is a pretty common theory. You've got a couple neat twists to it, though, so... good for you!

Here's my take on Pinkie being a wunderkind: my post on how to write the mane 6 (scroll down a bit to get to Pinkie's part); the first "meditation," where I respond to fics about Pinkie drinking coffee and going crazy; and the second "meditation," where I expand on her being a genius more.

4660153
I thought that this is pretty much what the show implied, that Pinkie always knew what was going on and always had it more-or-less under control, but has too much of a problem with taking things seriously enough to use her knowledge to help other ponies.

4660384 Yeah, I know it's not exacty a NEW theory, this is simply MY VERSION of it

4660373 Yeah, not a NEW theory, rather just my version of it

4660153
Also there's the fact that the ability to quickly learn musical instruments is considered a sign of intelligence. There's the parasprite episode, plus there's the crystal flugelhorn, and pretty sure we see her playing piano some time. And of course the big organ in the castle of the two sisters.

4661802 Yeah, I think she played piano in Appleloosa, in the episode when they go there to help with the conflict between ponies and bisons.
I could be wrong though, so don't qoute me on that.

However, she DOES play several instruments - and in the Parasprite episode, several AT ONCE.

And like you say, learning instruments can be a sign of intelligence, and to her it seems very easy,
almost as if she not ONLY has the edeitic memory, but she may also be a musical prodigy.

In fact, if she didn't have the balloon cutiemark, I believe a musical mark would've been the most likely alternative.

Another factor: she appears to have invented the helicopter.

4661846
No, she just sang in Appleloosa. Spike accompanied her on the piano.