Sometimes you only want to focus on a single idea at once. RemNote helps you ignore distractions by letting you "zoom" into any Rem by clicking on its bullet.
In RemNote, the only difference between a Rem and a Document is that Documents show up in the sidebar. You can "zoom in" to normal Rems as well just as you would zoom into a document. Thus, don't worry about breaking down your ideas into documents until you need to take a step back and get things organized. Once you want a Rem to appear in your sidebar as a Document, you can simply mark it as a document. (Read more in the tutorial on Documents and Folders.)