Everyone leaves and the hall is empty for 12 years.
Hey there!
First, we have to determine that "dressing" means really working harder and adopting a new set of ideals.
If you "dress" for the position you have, it means you're content and don't want to go higher.
However, if there's a position you want and don't have, you should be working hard to prepare and "dress" for it.
Hope this helps!
From the book directly:
"No animal must ever live in a house, or sleep in a bed, or wear clothes, or drink alcohol, or smoke tobacco, or touch money, or engage in trade. All habits of Man are evil. And above all, no animal must ever tyrannize over his own kind. Weak or strong, clever or simple, we are all brothers."
