ways to know you are DID and still be in denial -

a therapist without doing an evaluation for dissociative disorders diagnosis someone with DID. the client refuses the diagnosis.

going through a psychiatric evaluation for a problem not affiliated with DID example Schizophrenia. Dr's tell client that DID was one of the results.the client refuses the diagnosis

being co conscious with alters. the client knows the alters exist but denies the label of DID.

reading about the disorder turns the light bulb on that what you are reading about is similar to your own problems and symptoms (self diagnosing though not recommended and has a very high chance of being wrong in some cases can be accurate.

an alter goes through a psychiatric evaluation, the alter is given the results. therefore alter knows the diagnosis but the host does not. happens quite frequently. Alter tries to tell host but host denies the diagnosis.

suffice to say there are a lot of ways a person can be any disorder including DID and be able to deny that diagnosis.