INFECTION ON THE BRAIN

The medical term is infection on the brain 
You dear friend would consider me insane 
I don't do what normal folks around me do 
Something to consider please I ask of you 

I pack a case of clothes as I leave my door 
Not going anywhere so I don't know what for
I say hello to every passing complete stranger 
Not sure of the consequence or the danger 

Visiting shops is completely alien to me 
Why can't people understand and let me be ?
Insane I am but I don't know that I am insane 
The medical term is infection on the brain