To know each and every department within a hotel and how they function.
To understand not only the economy of the hotel but the economical situation where the hotel is.
To be able sell the product (rooms, events, f&b) and with that comes marketing and product knowledge.
In the end to manage a hotel is to manage a business so a bib is in order.
Lastly, service. Can you smile every time and understand your client and their initial expectations of your establishment?