@wctdoc1943 the friend I live with does exactly the same things. Leaves me waiting for almost 30 minutes at a spot in Costco, while he goes to get ONE item. Finally returns WITHOUT the item, grinning and happy as if he’d gone on some spree, with no awareness of my waiting. He is also becoming flustered when interrupted at a task, to which he has extreme uni-focus. And cannot do two things at once, such as continue a verbal chat while looking up a date on his phone.
I’ve been advised to consult medical help for him. Right. If he’s unaware and unwilling, I’m powerless.
Hang in there! Take care of yourself!