I'd like to elaborate on what I said, because some people make take it as me being dismissive of startup attempts. That wasn't my intention. But if you have launched a startup and never actually had a customer, then you've missed the quintessential characteristic of entrepreneurship. Lots of employees develop great ideas into prototypes within the confines of a company. If that's what you like to do, you don't need to be an entrepreneur to get paid to do it.

But starting a business means actually having to sell something. It's one thing to develop a product or service. It's an entirely different thing to sell it. Once your product/service is on the market, you have to deal with a whole bunch of problems that the first group of people who merely start a "business" but don't actually sell anything, will never have to encounter.

First and foremost, you actually will have customers. Customers are needy. Some are jerks. Some are wonderful and will send you cookies because you've brought a little sunshine to their life. But all customers have expectations and those expectations need to be serviced. Developing an idea into something tangible is in part a measure of somebody's ability to anticipate market needs. Dealing with customers is about how well you can react and fill in the things you did not anticipate or didn't get entirely correct.

Additionally, you'll have competitors. While your customers are pulling you in all sorts of directions with their own needs and wants, your competitors will be sizing you up in their sniper scopes. Having competitors is probably only one of a handful of things in modern life that resembles being prey. You know how fidgety squirrels are and how they are constantly scouring for food only to store it away for future use? Having competition is kind of like that. You will have to balance being a squirrel that is too safe and consequently gets mired down in fear with being one who is so haphazard that she gets mowed down by a car she forgot to look out for while running across the street.

If you have ever started a startup but never actually sold anything, you will never have encountered any customers. You might have encountered some competition that was so overwhelming that you never made it out of the womb, so-to-speak. And in that case, life is just unfair but you'll never know how well you would have stood up given equal footing. Regardless, having experience with customers and competitors are to me, the fundamentals of business. I think a lot of startups are great at developing things, but things are not products or services until they're actually sold.

If you like to develop things and are doing so at the moment, that does not make you a startup or a business. It means you like to develop things. Employees can do that. Employees can get paid very good money to do that. As an employee, you can even form your own little team and manage people like you would in a startup or a business. You can launch products and services as an employee too. But until you've found a way to sell that thing you've developed, I personally don't think you've started your business. A hotdog vendor down the street is way ahead of you in that respect.