Is something that my grandfather always told me.
As a tall kid, I did have a tendency to slouch.
Still being tall, it is something that I need to remind myself to do when sitting down. (Yes, I know, I am not standing when sitting, it is the shoulders back bit here).
Obviously this is good for your posture.
Though it is also good for your view of the world.
Standing up, with your shoulders back allows you to breath better, and deeper, if needed.
Which has the added benefit of calming us down.
Maybe that is something we should all remember to do…