I am traumogenic (trauma created/clinical DID) plural system. It is highly likely that I never had a "core personality" that I was born as and instead have always had either an infant mental state or multiple personalities. (During the time most babies begin to form a coherent personality, I formed several. It is possible that not every system forms like this but highly like I did)
Every time I've felt I was singular, I've experienced mental walls, amnesia and other DID symptoms. If someone could do a "I'm singular ama" that'd be cool because I have questions too. :)
its DID its just a subtype called depersonalization, no i dont have an alter just it all goes away and i become nothing. my hands dont feel like my own, everything feels fake and gray, my senses become dulled, you could break a bone and i wouldnt feel it, i become very mellow and still and unable to form coherent thoughts. happens randomly. cptsd has an opposite effect for me, i become hyperaware of my surroundings, pace, and i flip the fuck out and have definite triggers and crazy vivid flashbacks that mostly deal with bodily sensation.