The way I had Freguli-like expirences from my early childhood, is when I had profound symptoms of Prosopagnosia, when I saw everyone's faces, it looks like dark web mask, thought, and misidentified my family with others, because I thought that they are all the same.
I was aware that that I had severe developmental problems and was self-aware of Fregoli-like expirences throughout my childhood.
I knew that my beliefs were false, but my belief was still fixed, and sometimes misidentified my family with others, but I kept it to myself, because I knew that I would come off as strange.
I have been wondering. If it wasn't a delusion, I don't know what else to call it, because what I had is similar to Fregoli-like experiences.
I did have a little bit of anosognosia, but not to severe extent.