What’s the one position you simply can’t do?

What’s the one position you simply can’t do? I think it’s important to acknowledge that everyone has varying anatomy and poses that might be easy for some are impossible for others.

Mine is Happy Baby. I have a very mild form of scoliosis where one of my vertebrae protrudes posteriorly a little. It literally doesn’t affect my everyday life at all except when I’m trying to do Happy Baby. It feels like most of my weight just goes directly to that one vertebrae that is pushing into the floor and it’s super uncomfortable.