The first core principle of Zettelkasten is to write all the time in your own words, because if you do not write down or verbalize knowledge, it will be lost in your brain rather than stored externally.

When creating permanent notes, you should actively ask yourself what other existing notes this new idea relates to and create explicit links to those notes, because linking to only the bibliographic source is insufficient; true value comes from connecting the new idea to your existing knowledge network.

The second core principle of Zettelkasten is that everything is knowledge, including school textbooks, teacher lectures, personal experiences, memories, and shower thoughts, and the system treats all information non-hierarchically as equally valuable rather than privileging academic or formal sources.

When converting fleeting notes to permanent notes, you should ask yourself whether each captured moment is important enough to warrant a full note, and you can choose to write notes on paper first and transcribe them into Obsidian later, or type directly into Obsidian, or even avoid computers entirely as Nicholas Lumen did with physical index cards.

Because you have written all your ideas in your own words in advance and made pre-existing connections between them while taking notes across your classes and readings, when you sit down to write an essay or paper, the writing is already substantially done; your work becomes simply ordering the already-written notes coherently and connecting them with prose to make the paper flow.

Organization of undergraduate notes by course and source location (when and where learned) rather than by logical knowledge structure makes retrieval difficult because you must manually flip through multiple notebooks to find a specific thought, and you cannot fully remember when and where you originally learned a thought you want to reuse.

A knowledge management system is the missing piece that traditional note-taking tutorials on YouTube do not address, and the Zettelkasten method provides a holistic approach to storing and organizing interconnected notes.

The Zettelkasten method was originally developed by Nicholas Lumen in the 1960s as a physical system of interconnected index cards, and modern users have advantages over Lumen because computer software can automatically connect thoughts without manual cross-referencing.

The Zettelkasten system makes taking, storing, and learning notes fun and efficient enough that the effectiveness of the system itself creates motivation to continue using it, despite the inherent work required.

The third core principle of Zettelkasten is that a single irreducible thought is the basic unit of knowledge, and when taking a note you should make it as atomically simple as possible while remaining one complete thought so that it will make sense and be useful later.

The fourth core principle of Zettelkasten is that all knowledge is interconnected as a network of thoughts, and when storing a note you should actively ask yourself how it connects to existing notes and what you already know that relates to it, because the power and value of the system emerges from the quantity and quality of connections, not from individual notes.

Fleeting notes are the first step of Zettelkasten and are simply brief captures of knowledge, ideas, and thoughts that occur throughout the day, such as thoughts during a walk, audio memos, or lecture notes, which will later be processed into permanent notes.

When reading a book for Zettelkasten, you should not write notes in your own words during reading because doing so disrupts your immersion in the author's ideas; instead, you should use sticky notes to mark important moments and write down your own thoughts on larger sticky notes when the highlights alone would be insufficient.

When creating permanent notes from fleeting notes, you should write in your own words, make each idea as irreducible as possible, and importantly, you must record the source location (page number, chapter) so you never need to reference the original source again when reusing the note in future writing.

Nicholas Lumen's original Zettelkasten system used physical slip boxes with index cards, each assigned a unique identifier and manually cross-referenced to other cards by writing out identifiers, which was laborious compared to modern digital systems that automatically create and visualize links.

Obsidian is a software that stores notes as Markdown files on your local computer, allowing you to back them up to cloud services (like Google Drive) and ensuring you retain ownership and portability of your notes rather than being locked into a proprietary system.

In Obsidian, bibliographic notes are titled using the author's last name and publication date, followed by the full MLA citation, and then linked to a central bibliography note that automatically aggregates all sources referenced in the entire Zettelkasten system.

When creating permanent notes from source material, you should avoid including the source quote directly in the new note and instead paraphrase or summarize the idea in your own words, then create a separate link back to the bibliographic source with the page number, as paraphrasing ensures you process and understand the idea rather than simply storing a quote.

When naming permanent notes in Zettelkasten, you should name each note after the main idea or thesis it expresses, using double-bracket Markdown syntax to create the note title as a link, which allows you to immediately see the concept the note captures rather than using a date-based timestamp or arbitrary identifier.

Unique note identifiers in Zettelkasten must be distinctive across the entire system so that when you create a link to a note, it points to exactly one note and not multiple notes with the same name, and semantic naming by idea/thesis naturally ensures uniqueness in most cases.