For your flashcards, you will always be doing three things:

1. Building
2. Learning
3. Maintaining

Building refers to adding new flashcards (words, grammar points, example sentences, etc.) to your Anki decks. Learning is what happens when you first encounter those cards. After you first encounter them, they will become “Young" flashcards, and you will see them relatively frequently. In time, Anki will determine that you have completely memorized these flashcards, and they will be categorized as “Mature" flashcards. Maintaining refers to keeping these “Mature" cards in our memory by periodically reviewing them (in a systematic manner).

If you look at that image above, it says that I have 5,776 Unseen Cards. These are cards that I have already built (because they're in my decks), but I still haven't learned them, because I've never actually “studied" them in Anki. That is, Anki has not yet shown me these cards and said, hey, learn this!

There are also 645 “Young" cards. These are cards that Anki has shown me recently. I have already started studying them, but it's still too soon to say that I've memorized them. These make up for the bulk of my daily studies, because Anki shows them to me frequently, because I'm still prone to forgetting them.

Finally, I have 21,792 “Mature" cards. These are flashcards that I've finished learning and totally memorized. They make up a small percentage of my daily studies, because Anki only needs to periodically check that I still haven't forgotten them.

Currently in my daily studies, I am trying to learn 30 new Spanish words, 12 new Japanese words and 0 new Portuguese words. Because of this, the number and proportion of young cards in my Spanish deck is higher than the number and proportion of young cards in my Japanese deck and much higher than the number and proportion of young cards in my Portuguese deck:

• Spanish deck: 399 Young Cards; 11.8% of Studied Cards (399/3374)
• Japanese deck: 245 Young Cards; 1.4% of Studied Cards (245/17357)
• Portuguese deck: 1 Young Card; <0.1% of Total Cards (1/1071)

A great example of the power of Anki is that 1 Young Card I have in my Portuguese deck. It takes me about 1 minute to do my daily flashcards for Portuguese. Usually they are all very easy, because they are all Mature Cards. However, I must have recently forgotten one of those Mature Cards, so Anki dropped it down to “Young Card" status. Anki is making sure that I don't forget any of those 1,071 cards. Long story short, I am maintaining my 1,000 word vocabulary by doing 1 minute of flashcards per day.

The reason I say that these flashcards are so important to focus on in your studies is, first and foremost, that they can help you retain words and kanji at an extremely accelerated rate. However, there is also another reason we need to give them extra attention: It's very easy to fall behind on your Anki flashcards.

You pick an ambitious number of new cards to study each day. You keep up just fine, but then you start having a hard time keeping up with all the cards that Anki is telling you are due for review on a daily basis, and before you know it you have 5,000 cards due for review today, a number you'll never reach, and you've removed the intelligence from your 'intelligent flashcards.' Do not fall behind on your Anki flashcards. If you fall behind on your Anki flashcards, you will not learn Japanese in 1 year. So, if you notice you're starting to fall behind on these, you'll need to make it your #1 priority to get caught up at whatever means necessary. That probably means you stop adding new cards, temporarily. Like I've said 100 times, review cards are always more important than new cards. By reviewing, we maintain the database of vocabulary in our brains, never forgetting it.

At some point in your studies, you may have a couple hundred cards that are due for review on a given day, which could take an hour or more to get through. If you happen to break the chain on that day, then the next day you'd have an even higher number of cards due, maybe enough to take a couple of hours, even. Then, if you miss a couple more days, you've got over 1,000 cards due today, and you simply stop studying them… which means you stop learning at an accelerated rate, which means you stop making progress to Japanese fluency.

This is why we make our flashcard quotas our #1 study priority.