Sign: You think you know everything you need to know about how to run a successful business and there you don’t need any help or further education.
Why It Indicates inevitable failure: There are many activities that enable businesses to run successfully. These activities are; Marketing, Sales, Operations, Administration, Product/Service Development, Customer service, Supply Management, Stock & Inventory Management, Human Resources, including Training & development. Depending on how complex your business is & the type of business you run, there may be several sub-activities below these primary ones that you may need to master & execute. And even if you did master all of them, you would never have enough time to do all of them yourself and/or successfully guide the execution of those activities.
What to do about it: Figure out what your key strengths are, quickly. Learn how to do either Marketing or Sales very well. Give the rest of the work to/seek the guidance of people who know a lot more about the activities than you do.