I'm going to start by saying that I am not on meds and I have huge issues with my memory. I forget things people say, I put things down and instantly lose them. I forget what I'm doing, saying, or reading. I forget things I want to do later, even if it was really important to me or others. I go to the store and forget things even if I have a list.

This is part of cognitive function and it is a symptom in a lot of mental illness.

But losing track of time and what day it is may not be. But, I used to forget to eat all the time when I was at home and not working.