A man stands straight – his deportment mimics the way he lives his life – erect, proud. Shoulders back, chest out – but not ostentatiously so; as in all things, a gentleman strives to face the world in the best way, but not to be an object of show or ridicule.
A man who slouches, or who contorts himself like a pretzel, shows a lack of confidence in dealing with the world. Existentially, a man knows that the world is a difficult and dangerous place, but he also knows that defiance – standing straight into the teeth of the storm – not reticence, is the best way to face an unjust, irrational universe.
If the storm blows him over, literally or metaphorically, he gets up, brushes himself off, and stands up straight once again. And again.