@Keith Mowz  
Maybe. Still, “Ponies can change their names” is now canon, so it does lend some credence to this headcanon.

@digiman619  
I think that was implied to be a marital name change.

Well, we don’t know if they can do it after they get their CMs, but we now know that a pony can change their name. Just ask Chiffon Swirl, aka Mrs Cake.

@Background Pony #DB73  
Magic and qi often causes hyper intuition in magicians and martial artists… And Youkai, I guess, since they’re also powered by qi, not magic. X3

@Background Pony #660B  
Seems reasonable to me. Well, considering this is a land of magical talking pastel equines, that is.

Somehow, I’m more comfortable with the headcanon that when a parent names their child, the name fits their talent due to the hidden potential somehow being subliminally messaged telepathically/magically to the one desciding the name of the foal.
 
Yet, it seems kinda stupid when I type it out like that…

@Squirmy Hooves  
Chester Matthew doesn’t fit the pony-name format.  
…Chestnut does, however. :3

@Dashy  
Yup, her name is “Pinkamena Diane Pie”.

This is in fact my headcanon, but to be fair, he never said his name was anything different before the CM, and the coloration is generally right.

@qmm1337  
Still Cheese Sandwich. Just did not tell anyone. Or maybe something that can be shortened to it, like Chester Matthew Sandwich.

Wait, what was his name before?

This was already my headcanon.

No mention of Twilight’s connection to the entire galaxy?… :T

@Vree  
Or, maybe she is destined to have a job as an acrobat\scooter rider, but getting her CM for something completely different.
 
Or maybe (since pegasi do not raise their kid stuff) she is supposed to get her CM while in the presence of both her bio-parents, or after some stuff such as one of the Mane 6 s’ deaths. Heck, maybe she is supposed to get her CM on the day of her 21st birthday, or some other age.

@Squirmy Hooves  
I’m forced to accept the prophetic dream theory with an extra sprinkle of mental blind spot because of evidence from the show, where a blank flank named Scootaloo who likes riding a scooter can’t figure out what his special talent is.

@thps48  
Yup. Maybe when ponies are pregnant, they receive a prophecy or dream of what their kid will do and what would be their Cutie Mark, but these prophecies are vague (maybe they see a blurred image of their kids getting a CM, or hear a blurred voice) and the fated CM may change.
 
An unicorn named Tess Swirleen and a pegasus named Cloudy Bottoming decide to have a kid. When Tess is pregnant, she receives a prophecy that her kid will get a CM for baking cakes. 11 months later or whatever, little unicorn Batter Bubbles is born. Tess dies right after Batter’s birth, and due to “pegasi do not raise their kids” stuff, Cloudy is an imbranate parent, and drops Batter in the Everfree Forest while flying. She gets found by some timberwolves that start to raise her, basically becoming a wild-child. She eats some Poison Joke causing her to turn into an uncontrollable wolf-pony, that starts eating everything until she falls into a coma and gets found by Zecora, that renames her Dulake, and starts the search for her parents. When Zecora realizes Cloudy and Tess are both dead (Cloudy was killed by some unicorn street gang, and Tess had an heart attack), she decides to give her up for adoption. Fluttershy instead finds her and decides to make Dulake live with her until she gets her CM. Dulake\Batter Bubbles is taking care of a squirrel, when she gets a CM for… healing powers.
 
Batter Bubbles’ destiny\fate was changed, she was supposed to be a baker, but now, she is a veterinarian\nurse type.

Your name is foretold by the stars. The secret is that the cosmos is commanded by a mysterious purple pony from the future… Or Celestia… In the present… <.<

@phatboy55  
Yup.
 
He did not tell anyone what his name was, then he went to Pinkie Pie s’ birthday party, and then he told everyone that his name was Cheese Sandwich.

Perhaps Pinkie’s not just a nickname but her real name?

what if his name as “cheese sandwich” a coincidence….  
an incredible coincidence like always.

@Squirmy Hooves  
Maybe is just a nickname?

I thought his name was always Cheese Sandwich. He just didn’t tell anyone.

@Shadow_the_Hedgehog
 
@Senile Old Pony
 
Well, it could be a common-ish thing, and certainly one that you would do if your name was, say, Sweetie Swirl (parents wanted you to be a baker) and you ended up with a knife on your butt, representing that you’re officially one of the snarkiest Earth Ponies ever. Maybe Cheese Sandwich s’ birth name is “Brick Break”.

Mmmm… That’s an interesting theory.

Do you think this is a common thing?  
And do you think its easier to do then in real life? I haven’t done it myself though it doubt its as easy as changing a password.