It's more than possible! Most of us are not dxd w/ DID until we are well into adulthood...not knowing u have DID is a fairly hallmark trait, as is not realizing missing time/memories until they are presented to you from outside. Also,can be confusing to differentiate from PTSD depending on how it presents and a lot of times lacking younger parental/ other adult authority figures accounts of any "off" behavior... For me, I think as a young child it is all we know so we don't remember or view it as anything being odd....then teen and adult yrs, just like others around us, and a lot of times Dr's as well....we strive to justify, cover up or invalidate any possible signs or symptoms bc
A. It is a very difficult and wildly buzzard notion to come to terms with accepting
B.Controrversial for many and even don't believe it is a real disorder...so easier to fathom any other causation as more likely ie. Drug addiction or severely Dramatic PD/factional disorder etc..even if no tangible proof of those exist.
C. Usually is accompanied by other dxs...often many that many be seen in all some or just on individual part (alter)..can be confusing and difficult to figure what the what is....
D. It is the first and sometimes the only survival/ defense tool we know/learned. And as such, with or without knowledge of any other parts, time/memory disturbances, odd behaviours, stuff we can account for etc...we will defend ourselves as "normal" at all costs (until we are able and feel safe enough to disclose otherwise), bc we see it as both vitally essential to our survival and safety and also are terrified of being viewed as freaks or crazy or locked up for life on a thorazine drip, and lastly probably the scariest outcome of "knowing/revealing"...Having to face our true selves and possibly uncover and relive our initial trauma...which is what is the most critical thing that why we are is, to protect us against ever having to know or relive that memory.
I can not say whether or not any if this applies to you or not...only answering the title post question if u can have DID n not know....answer is resoundingly YES.