I know a guy, about 50 years old. He is a self-taught programmer since he was young, and he has always used Visual Basic (never anything newer than VB6).

He once needed to interface with a web application I wrote, so I asked him to send me a POST HTTP request. He didn't know what I was talking about. No notion of REST, sockets, HTTP, nothing.

The he showed me his code. Actually, his codes. He had multiple copies of the project, one for each version, and he even kept multiple variations of the software in different separate folders. He probably doesn't know what "version control" even means.
You think this is messy. You didn't see the actual code (it's a huge application!).

Spaghetti all over the place. Meaningful variable names, what are they? Default names for the controls, like button1, button2, etc, with forms with more than 30 buttons and text fields. This was the most incomprensibile code I have ever seen.

You might think that this guy is just a hobbyist.
No.
He sells his applications. To companies. They are obviously full of errors, but they buy them.

Now, if you're still with me, two questions come into my mind:

- why?? I hate this, because it's impossible to prove to a non-technical person that this is *not* software development.
- how do I know that, to someone else, I am not like him? How can I be sure that I know and will know what needs to be known?