We consider how new ideas emerge from others in federated hypertext. Both author and reader recall by association as they process speech acts. Research shows that ... um ... but I digress.
If something you reading or writing reminds you of something you find interesting then write that something down immediately.
Split the paragraph you were reading. Write a few words in the new paragraph that will hold the idea while you complete this workflow.
Scan the nearby paragraphs thinking about where best your idea might fit into a future readers thought process.
Move your words to that best location.
Expand your idea into a complete paragraph. Assume the context is sufficient for understanding your idea even if that is not true yet.
Add a link to a more complete exposition of your idea if you have one handy.
Now ask yourself, does this idea advance the goal of this page declared in its title and synopsis or is it a digression?
If it digresses, ask yourself where it might better fit in. Name that place with a short phrase. Cite that page in another new paragraph.
See Internal Link Style Guide
Create the new page. Write a synopsis. Prepare the reader to encounter your idea in a context where it belongs.
Drag your digression to this page, its new home.