After playing Path of Exile for 13 years (started in closed beta in 2011), I finally found my first raw Mirror of Kalandra drop. But it wasn't just a single mirror of Kalandra. It was two of them at once. :)
For non-poe players: This is one of the most rare drops in video games. Most players will never have a single one of these drop while playing the game, even if playing since closed beta like me.