I got told I could never sit straight as a kid - I'd sit in every position but the correct one. Knees up, slouching down to the point of almost lying down, sittting sideways... no wonder I had issues with my posture for a while! Sitting down on the ground... I remember as a kid I'd try to do the 'Buddha sit' which is what we called it in my Chinese family, not sure what it's called elsewhere or just Asian squat because it was more comfortable apparently? I'm a bit better now, I mostly sit normally but will rest my chin on my hand a lot. Also will just sit cross legged now. Sometimes still get in the habit of putting my feet up, its a bad habit from when I was younger :'(