So this is fairly likely to do nothing against a Modern B/x(/y) Midrange/Tempo opponent such as Jund or RB Prowess or an aggro opponent...got it.
That's why it's a Lesson. The baseline here is a card that will almost always be worse than Divination, but the whole point is that you'll fetch it when it's an undercosted Concentrate, then fetch Reduce to Memory instead when your opponent already emptied his hand, or cards like Academic Probation and Illuminate History when there's nothing else going on and just need some extra tempo or setup respectively. These cards are designed to be slightly weaker silver bullets.
It's like Tales of the Ancestors, but a set value instead of 100% catch up.
Source: MythicMikaela
As a sorcery, an opponent can stay basically hellbent if they have to and they have control over it.
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Why this card is a rare is buffling, this could just be an uncommon.
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