Y’know, that makes sense actually. Reminds me of my chairs (Aerons) which, unlike some chairs, promote zero movement and require you to sit in the “proper” position. Like your case, this works best for me because otherwise I am prone to hurting myself by sitting like a shrimp.

It didn’t work for me in mattress form (though for me, it was uncomfortable enough that I moved more), and I ended up being one of the people who got pain from it, but that’s the case with chairs too. Bodies are so damn weird and there truly is no fit-all solution.

That’s actually the other reason I said it’s not that you have bad mattress taste or anything— mattresses are so personal, thanks to bodies being so variable, that trying and returning is the way to go. Mattress companies know everyone is different so they deliberately offer 365 day return periods. In the old mattress sub people were buying mattresses, testing them, then returning them if it didn’t work (the office chair subreddit did this too). It’s actively encouraged by the companies and doesn’t hurt much because mattress margins are huge to begin with.