I feel like this is one of the things beginner programmers eventually figure out on their own without having to be told about it, otherwise they'd never be able to complete fairly basic programs but large programs which touch a lot of systems.

You'd have to be really new to write a bunch of code without ever testing it working incrementally, likely because you've never encountered it before. A couple of painful debugging sessions will quickly make you realize you need to test your assumptions one by one in the right order if you are to ever have a chance of making an unknown program (i.e. a program you are writing for the first time) work. All the stars have to align, because one wrong error will throw everything right off. Debugging is the act of visiting each possible source of error and validating it works. The best way to do this is to build the program incrementally (which again, I expect programmers to quickly realize).