According to the comprehensive rules: if there are fewer than N cards in your library, you may reveal all the cards in your library. If you cast a card with ripple 4, and there are only 3 cards in your library, you will just reveal all three of those cards
Flying, first strike Whenever Sidar Jabari deals combat damage to a player, return target Knight creature card from your graveyard to the battlefield
Note: Some card effects like mass land destruction spells, would have dominated the list
And I didn't even go to many Grand Prix
scan cards and/or fetch prices, data processing may take place
I don't imagine you'll be doing this very often, but maybe you're out of Lessons, so you planned to discard, but some things happened in response, and one thing led to another, and now it's time to learn, but you have an empty hand, and this is all very embarrassing, and let's just not speak of it again, okay