This is true.
The main thing that made a difference for me is paying attention to code organization. Organising large project - What do you think of my solution? what are yours? - #7 by jamshark70 explains some of my approach. (Note, when that post refers to my SC book chapter, that’s the first edition.)
If you’re storing all your resources in global variables and throwing about bits of code without much discipline, once you pass a certain threshold of complexity, you will definitely get confused. By contrast, I’ve been able to build some quite complex behaviors into my live coding environment that I’m pretty sure would have been prohibitively difficult without encapsulating resources into objects that make sense.
hjh