Using Freudian language, the ego denotes a sort of baseline state of a personality, but that’s not the usage I wish to convey here. Here, I wish to mean “ego” in the more colloquial sense to convey arrogance.
Always — but especially when running your own business — projecting a small ego is essential. Customers want to accomplish some goal (we hope!), and they look to vendors to provide solutions. A narcissistic ego is a distraction that doesn’t really do your customers any good.
Sales is essential to success. Nowadays, a prevailing notion is that AI can and will do everything, but selling is primarily a “soft skill” that relies heavily on adapting to subtle cues—not exactly AI’s forte.
Running a business entails selling. In fact, every company relies on sales. Even in businesses that ostensibly rely on other roles, like product development and support, those roles are ultimately supporting sales; giving sales something to sell and helping the customers.
When building a business of any size, it’s essential to sell something. I see discussions around “PMF” as entrepreneurs seek to identify markets, but an extremely important facet of that is remembering that when a product fits a market, there is still work to be done. Specifically, even when PMF is achieved from the product standpoint, somebody still needs to sell it, which is likely to kick off new rounds of: feature requests, revisions, advertising/marketing, customer profiling, and so on.
Budgeting is essential when planning and/or running any business. At the most basic level, you want to assure that if you spend $1, you get more than that in return. This is how you know you have a business and not a hobby.
In order to run a business well, you need to know how much things cost and how long they take. If you can quantify them well, you can compare them, allowing you to evaluate them.