Why you shouldn't use your friend's flashcards

It is Sunday night. You have a midterm on Tuesday. You haven't touched the last three weeks of lecture slides, so you do the logical thing: you message the group chat. Someone sends over a Quizlet link or an Anki .apkg file. You feel a massive sense of relief. You just saved five hours of work.

But then you start the cards. Ten minutes in, you hit a card that says "The Big Blue Thing" on the front and "Atmospheric refraction" on the back. You stare at it. Why did your friend write that? Was there a specific slide with a blue diagram? Was it a joke the professor made?

You spend thirty seconds trying to decode a card that should have taken three. By the end of the session, you are more confused than when you started.

I work on Nebulearn, so I have a bias toward making the card-creation process as fast as possible. I want you to make your own cards because I built the tool to do it. But even if you use Anki or a notebook, the "time-saving" logic of using someone else's cards is usually a trap.

The Encoding-Storage-Retrieval loop

To understand why shared decks fail, you have to look at how memory actually works. Cognitive science generally breaks memory down into a three-step loop: encoding, storage, and retrieval.

Encoding is the process of taking new information and translating it into a format your brain understands. When you read a textbook and decide how to turn a paragraph into a question, you are encoding. You are connecting the new fact to things you already know.

Storage is keeping that information over time. This is where spaced repetition algorithms like FSRS (which we use by default at Nebulearn) come in.

Retrieval is the act of pulling that info back out during a test.

When you download a friend's deck, you are skipping the encoding step entirely. You are trying to store and retrieve information that your brain never actually processed. It is like trying to install a software update for a program you haven't downloaded yet.

The "What did they mean by this?" tax

The biggest hidden cost of shared decks is the mental friction during reviews. I call this the "context tax."

When you make your own cards, the back of the card is a trigger for a memory you already have. You remember the moment you typed it. When you use someone else's cards, you aren't just memorizing the fact; you are memorizing their specific, often weird, way of phrasing it.

Common symptoms of the context tax include:

• Inside jokes: Your friend used a nickname for a protein that makes sense only to them.
• Personal mnemonics: They used an acronym based on their childhood dog's name.
• Missing links: They grouped three concepts together because they "feel" similar, but you don't see the connection.

Every time you hit one of these cards, you stop. You lose your flow. You might even have to open the slides anyway to see what the card is talking about. At that point, the time you "saved" by not making the card is officially gone.

When shared decks actually work

I don't want to be dogmatic. There are times when using someone else's work is the right move.

If you are a medical student using the AnKing deck, you are using a resource that has been refined by thousands of people. The "context tax" is lower because the cards are standardized and high-quality. Similarly, if you are in a rush for a Friday morning quiz and your friend sends a Quizlet set that exactly matches the vocab list, go ahead and cram it.

Anki is great for these massive, pre-made community decks. If you have a 10,000-card deck for a language or a board exam, Anki is the gold standard. But for most classes, the debate of premade Anki decks vs. making your own usually ends with you needing your own context to actually pass.

But for your specific university courses (like the ones I take at UofT), the material is usually too specific to the professor's whims. A deck made for a biology course at one school might be 40% irrelevant at another.

Feature	Making Your Own	Using a Shared Deck
Setup Time	High (initially)	Zero
Review Speed	Fast (high context)	Slow (low context)
Retention	Stronger encoding	Weaker encoding
Accuracy	You verify the facts	You trust their typos

How to close the creation gap

The real reason people use shared decks isn't because they think the cards are better. It's because making cards is boring and takes forever.

If you can make the flashcard creation process faster, the temptation to use a "bad" shared deck disappears. The goal is to make encoding so cheap that you don't feel the need to skip it.

I usually tell people to focus on writing cards that stick by keeping them atomic. One card, one idea. If you try to copy a friend's "big" cards that cover half a slide, you will struggle to remember them. If you make your own small ones, you'll breeze through the queue.

The verdict on sharing

Using someone else's flashcards is a debt you pay back with interest during every study session. You save an hour on Sunday and lose three hours over the next month because you're fighting against someone else's brain.

I built Nebulearn specifically for people who are tired of that trade-off. If making cards took two clicks instead of two minutes, you wouldn't need your friend's deck. You could just highlight a sentence in your lecture PDF, hit a keybind, and have a card ready to go with your own context and your own voice.

If you are currently drowning in a shared deck and finding it harder than the actual exam, it might be time to stop. Delete the deck, grab your slides, and start encoding for yourself.