<muffled "IT'S NOT A MENTAL ILLNESS!" in the background>
Real DID is extremely rare, and the condition itself gained popularity after one Daniel Keyes wrote his novels The Fifth Sally and The Minds of Billy Milligan, the latter being a non-fiction portrayal of the first person acquitted of a major crime after being officially diagnosed with DID. The case itself was highly publicized, but took place decades before the majority of these people were born.
I have no idea where they picked this "headmates" shit up, but it's just another romaticization of a very serious mental condition, and is nowhere near like the real deal.
Not only that, DID (originally called MPD or "multiple personality disorder") is an exclusively western phenomenon. The person with the first known diagnosis of MPD when it was called such even "gained" around a dozen new personalities in order to push the illusion, and if I recall correctly the man who was acquitted for having it admitted to have been lying and inspired by said case. The reason it was renamed to "dissociative identity disorder" is because it is instead classified as a form of dissociation, a mental defense mechanism for those undergoing extreme mental duress, akin to "out of body experiences" or a "fugue" for people suffering from extreme stress or PTSD.
Now, the important thing is that although it's classified in the DMS-5, it doesn't actually have a biological signifier as far as I know, so it's by all means a method of dissociation as I said. It's a mental coping mechanism, so when these people prance around without a care in the world claiming to have DID, it's highly questionable. But since it's a
dissociation disorder, you wouldn't be aware you'd had it until after the fact. Doing so is as if a shell-shocked soldier from WWII started trembling from a panic attack while announcing "tee hee, I'm having another episode!" You'd even be incredulous or angry for somebody inform you that you were experiencing dissociation, since it's a means of coping with extreme stress and thus an escape mechanism. But, most importantly,
you wouldn't be aware of your other "personalities," let alone sending messages to and from it. The fact that commenter referred to himself as a "system" is a huge, crimson flag that it's nothing more than attention seeking.
Now, the attention seeking is just annoying. What disgusts me is the gleeful abuse of mental disorders for the sake of attention seeking. You're not some soldier who watched his friends die, or an innocent person who was nearly killed in a car wreck. You're some prissy mommy's boy playing pretend on the internet who probably hasn't worked a day in their life.