I'm a dev who's starting a business and running up against some of this -- for me 'understand the entire market' resonated.

In my case that means knowing the major datapoints about competitors in my space (public vs private companies, who's making/losing money, appannie stats), knowing everything available about cost of user acquisition, and looking at psych studies on user motivations.

These are things I would have benefited from knowing on day 0 but instead only learned after building a prototype that I had to scrap.

If your business is enterprise focused rather than consumer focused, understanding one or two customers is probably good enough for a start.

Seriously. Your proof that you understand a market is only as good as the frequency that your understanding is tested, whether the test is profits or rote knowledge.

This is true for many things. I'm the best developer as long as I don't compare myself to a better developer.

Also, make sure not to confuse understanding your customers with understanding how the industry works.

Some of the craziest and successful startup ideas come from people who don't understand the industry at all and if they had they probably would have never tried to do what they did.

Survivorship bias. Some of the biggest flops also come from people who don't understand the industry at all, and if they had they probably would have never tried to do what they did.

You can't understand your customers if you don't understand their industry. Picking customers is like investing: if you pick a bunch of customers that are not going to win their industry, you won't thrive either.

That may be true, but it isn't a reason not to try. Heck in the process you may learn the industry, just too late for current venture. It is however a reason to be willing to recognise a flop and abandon it for something else.

Yes, but what I'm actually trying to do is cast suspicion on the dichotomy between industry and customers. Industry is not a thing that exists. There are only people, their objectives, their resources, and their problems. Those are the things that need understanding.

Perhaps I chose the wrong word. I was looking for a word to describe the biases of people entrenched within an industry.

I don't think that's what the parent meant: your time is better spent understanding the whole market than a subset, and your time is better spent getting the important trivial thing done now than working on the not-as-important nontrivial thing.