I’ve found doing a “fake commute” where I go for a walk for 30-60 minutes after work is pretty helpful.

being able to decompress walking around a leafy park is much better than trying to decompress stuck in a busy train with no seats.

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.

> How do you disconnect and shutdown the problem solving part of your brain?

I dont.

Instead, I substitute MY OWN projects and goals and things INSTEAD OF work's goals. So instead of killing my innate curiosity and problem solving, I change its focus to serve me.

You need to do this even if you don't subscribe to the idea of work life separation. You'll find better solutions to complex problems if you can rest, exercise, pursue a hobby or other distraction for part of each day. The subconscious needs recruitment for anything non trivial. Log it and state the problem that isn't yet solved explicitly in writing. Then affirm to yourself that you will come back with a solution.

Not OP but many years of working from home.

The best thing I've found is Logseq. Any other note taking app would probably do, but the important thing is that it's a "daily journal" style where I brain dump relevant things into bullet points. This has come in really handy for many other reasons as well.

I've been using Logseq for the last few months and it's wildly better for me than using things like Evernote for this. I used to be big on having a lot of structure in terms of notebooks and notes, a lot of which contained project journals of one sort or another. But the way Logseq makes journaling a primary interface makes things much easier. I tag some things I want to be able to find later, or link them to pages. But I have a lot fewer dedicated pages now, and have to worry a lot less about maintaining consistency in some sort of broad ontology.

I use paper. Sometimes I refer back to the last few pages but rarely go back further than that. 99% things... Seem like really good ideas but if they don't stick then they probably don't need a dedicated home. And if they do stick.. well, I'll have to flip a few pages and copy them into my personal wiki or something so they can have a longer life.

I leave my home office and connect with my kids or go outside. Just the action of getting up and leaving the work space and starting a new activity seems to do the trick for me, YMMV of course.