Sudden Insight

• WWizards of the Coast2021-07-23
  Official Ruling
  If a card in your graveyard has in its mana cost, X is 0 when determining that card's mana value.
• WWizards of the Coast2021-07-23
  Official Ruling
  Although land cards aren't considered, nonland cards with mana value 0 are. For example if the cards in your graveyard are an artifact card with mana cost and a sorcery card with mana cost , you'll draw two cards.

Rulings via Scryfall