Luckily there is no such thing as "correct posture".

Sure, but getting the right environment is a prerequisite. In my case it’s a Herman Miller Embody chair [1] that stops me getting into a bad position (it’s not impossible, it just encourages good posture).

[1] https://www.hermanmiller.com/en_gb/products/seating/office-c...

if im not sitting on my right foot with left knee under my chin my thinking takes a hit, but i also have to constantly switch how im sitting so i dont get annoyed. its hard not to slouch/melt into whatever im sitting on and i think the only way to offset all that is the gym.