First off, it means that a series of traumatic, abusive, horrific and overwhelming events happened to you, damaging your sense of self and splitting off various ego states along with the memories of the incidents.
These memories will slowly/quickly/ unexpectedly come back, at some point, in the form of flashbacks, in which you will find yourself reliving the trauma. Sometimes I can see, physically feel, hear sounds and words, even smell what the event was like way back when it first happened.
Often, I wake up in the morning, the middle of the night, after a nap, and have to orient myself to where I am, what city, is it day or night, what was I doing before I lay down, what is on the agenda of things needing doing, when was the last time I ate, is it time for meds? Usually not all at once, maybe 3-5 of those most times I awake.
It feels like I'm wearing my body like an ill-fitted suit. It can feel too big, awkward, clumsy or even robotic and it's movements are completely out of my control.
Sometimes I can feel my lips moving but I can't hear the words. I frequently and without any forethought refer to myself as "us" or "we". I don't consider myself a singular person, rather a group of related individuals varying in age from early childhood, toddler, preteen, teenager, young adults and adults, Littles (for those under 10; teens for, well, the teenage parts of me, aka "alters" for alternate personalities and Bigs, for anyone over 21.
When I switch/change into another personality, my vision change and colors may suddenly look very bright, dull and fuzzy, or crystal clear.
I've had numerous times where I've tried saying certain words and they sound like a child's vocabulary instead of an adults. I can suddenly start stuttering, stammering or go completely mute at any second, mostly just in therapy.
Sometimes it feels like I'm looking out through someone else's eyes.
It's not a normal daily life by any means. These are just some of the ways that I think being a multiple is different from being a singleton.
It's not bad or awful, just different.