When we’re unable to answer a question, it tells us we need to return to the material to review or relearn it. In a sense, this is a sort of reality reconciliation akin to checkins, therapy, OmniFocus Reviews, and the like. The “Study Deck” item in the Tools menu allows you to quickly switch to a deck with the keyboard. You can trigger it with the `/` key. When opened, it will display all of your decks and show a filter area at the top. As you type characters, Anki will display only decks matching the characters you type. You can add a space to separate multiple search terms, and Anki will show only decks that match all the terms.