I feel like the other 3 points above all help with this. That's not to say that I don't log off, and still think about something I'm working on, or wake up thin

I feel like the other 3 points above all help with this. That's not to say that I don't log off, and still think about something I'm working on, or wake up thinking about it (this depends on what I'm working on, how much pressure I'm feeling, and how complex/interesting it is). But honestly, this doesn't feel any different than it always did. Pre-smartphones, I still would sometimes drive home and think about what I was working on on the way home, or "bring work home" with me. I think the brain thing is (mostly) independent of the WFH/WFO thing -- as long as you're doing the other three things above. Otherwise, the brain thing is compounded.