I guess this is a form of dissociation or a memory issue, maybe both.
I've had a lot of stress lately, and someone I met asked me how many tattoos I have. I told them I had 2 tattoos instead of 3. I was unable to remember what my third tattoo was and where it was. I had to look down at my wrist before I remembered what my third tattoo was... it's literally right there, on my arm.
I've had plenty of memory and concentration issues before, maybe it's just a part of that.
I think dissociation, or C-PTSD has a lot to do with memory issues... it happens to me so I can relate to your post, although I have no tattoos.