How Do You Know When You Dissociate?

I looked through some of the threads and maybe this has already been posted somewhere so forgive me if I am being redundant. How do you know when you are dissociating? A few years ago I was seeing my nurse practitioner (psychiatrist shortage where I lived) for meds and we were talking and then I looked up and she said "where did you go just now?" I had no idea, I guess I just blanked out but couldn t recall anything I was thinking. Now I wonder how often I do this and don t even realize it.... How Do You Know When You Dissociate?
https://www.myptsd.com/c/threads/how-do-you-know-when-you-dissociate.12849/