How far back has ,has he gone

[IMSOSAD]

I confused as to , how far my father has gone in his dementia, he does not know who i'am most of the time, also he mentions his brother and also ask's about his father, how can the consultant tell how far back he has gone . I know that some people have put a age on their loved ones,

[Grannie G]

I don`t think they go back permanently. Well my husband doesn`t. He is 79 and will ask where his mother is but still knows me and our son.
I doubt anyone can tell how far back a person is and is there anything to be gained by trying to work it out.
The best thing to do, if you can, is try to be where your father is.