No one person has all the skills, knowledge, or the complete understanding of everything that is required to successfully run and grow a business.  It's just not humanly possible.  It doesn't matter if it's a small business or a larger business.  There are too many complexities to address. 

Accepting this premise from the beginning increases the likelihood of your growth and your success.  Acknowledging this is a strength, not a weakness.  It means that your ego is in check and your goals are to serve your customer, first and foremost.  And let's be honest, serving your customer well, is what makes a business soar.