I've met a few programmers in my career who were able to write a huge amount of code doing wonderful things without testing at all. One guy I think of would spend days coding without even trying to compile his code and apparently, except for minor typos he could quickly fix, his code was working when he decided to compile and test it. He impressed bosses and colleagues with amazing features developed in a very short time but, on the other hand, nobody on the team was able to maintain his code. This was explicitly stated and accepted by team members, we knew we couldn't maintain his code but we were ready to accept it given the productivity of the guy. It was a trade-off.
This way of working is completely alien to me. I can't think things in my head out of nothing and write working code. I need to start building something and get feedback from the computer to go to the next step. That's why when I was introduced to TDD it immediately made a lot of sense to me. It matched the way I was already operating. If I didn't have this workflow I think I would be unable to write even mildly complex code.
It's interesting how people can operate differently. In a way I'm a bit jealous of those "zone" programmers who can produce amazing things very quickly. But, on the other hand, I can see that I'm also useful because companies hire me and want to keep me. I've seen many times people taking over my code, maintain it and develop it further. I've even been explicitly told a few times that my code was very easy to understand and maintain. Seeing people taking over my code and develop it further is one of the most satisfying things in my work.