I was getting some personal numbers (ssn, DOB, insurance ID# etc.) from a guy who was in his late seventies the other day and he kept putting the number 300 in there where it didn’t belong. It didn’t take me lond to figure out, especially since a social only has 9 digits, but when I did, I noticed it every time he did it. He was otherwise coherent, but the manner in which the number seemed to insert itself into his thoughts suggested to me that it might have been more than just absent mindedness.
I thought it might be either dementia or Alzheimer’s, possibly the beginnings of garden variety senility, but IANAD. Does this sound like anything specific to any of you?