The 'Not me'

This morning I had one of those "wonderful" occasions where I wake up (at 6am) and the whole day feels like I'm not me. I'm sure you've had those days too. Where you feel as if you are physically moving one step behind yourself.
The 'not me' however is always super annoying, feeling moody, confused, very groggy and disorientated and I spend the entire day feeling like I'm sat behind someone else who is essentially driving my body for a day.
I never understand why the 'not me' can't be a super productive version who cleans my house, bakes some fresh goodies and irons everything. While the 'real me' sits back with her feet up just coasting along. No, the 'not me' has to be a confused geriatric who can't even remember basic names and tasks. Perhaps it's future me from the year 2086 whose popped her clogs but won a "day in the life of" young me.
She must be very disappointed, I'm never doing anything even remotely interesting when I get occupied by 'not me'.
And to confuse myself further, I actually spend large sections of the day sitting quietly asking myself...if I am me, I sure don't feel like me. I begin to hear 'duuuuuuhhhh?' and high pitched static 'white noise' through my mind at intervals throughout the day, as if, perhaps, future me - is a zombie.
Maybe it's time to get ready for Zomb'ocolypse circa 2086 - you'll know when it's coming, we'll get that oh-so-familiar vacant look in our eyes and start forgetting where we are going and what our names are.

But enough with the side order of crazy, I've got me some working to.....um....what was I doing here again?