Go to bed!

Lasr night I woke up around 4am  0 went to the bathroom - checked in on my dad and sure enough he wasn't in his bed asleep - his bed was made up and his clothes were not at the end of the bed. I came downstairs and found hum fully dressed sitting in his recliner reading the newspaper (he had already read the paper three times during the day).
me - "Dad, it's 4 in the morning - come to bed."
dad - "I am reading this"
me - " You already read that, in fact you read it three times - come to bed"
dad - "How do you know?"
me - "Because I saw you reading it earlier today - come to bed"
dad - just sat there and kept flipping the pages - not reading a thing just being obstinate
me - "Dad stop reading that paper. It is time to got to bed"
dad - ignoring me
me - "I am not going away until you get going back upstairs - go to bed dad!"
dad - srares at me blankly
me - now I a getting mad - I can't have him downstairs at 4am alone with the potential that he goes outside and wanders away  I start yelling "go to bed dad!"
dad - just stares
me - "go to bed dad - that's an order!"
dad - finally a response - he takes the paper and folds it up and shakes it at me."what are you crazy?'
me - "Yes dad I am crazy - go to bed!!!!"
dad - stands up "are you crazy?!"
me - "Yes Dad! Go to bed!!!!"
dad - " You can't treat people like this!" he was so angry
me - "GO TO BED! - I will be right behind you"
dad - "what for?"
me - "to make sure you don't fall down the stairs and that you go to bed"
dad - walks slowly up the stairs and back into his room
me - laid in bed awake for an hour I was so worked up  - plus I had to make sure he didn't come right back downstairs

Dad then slept until 10am. It is so hard. I think he just wakes up probably with the need to go the bathroom and just doesn't have any sense to then get back into bed and go back to sleep. Instead he knows he is awake so he gets dressed, makes his bed and wanders downstairs. What is hard to understand is why sme things stay in his memory and others don't  - his entire adult life he woke up every morning brushed his teeth, shaved and showered. I don't think he brushes his teeth very often, when I ask him about it he says that he does but I know that the same tube of toothpaste has been in his bathroom since last Fall and there is still a whole lot in it. He shaves every few days (usually after I have prompted him to do it several times) and he now showers maybe once a week - after a lot of prompting...

this disease just sucks...