Reduce to Memory — ruling 1

Lesson is a spell subtype found on some instant and sorcery cards in the Strixhaven set. The Lesson subtype has no special rules associated with it.

Reduce to Memory — ruling 2

Although you may want to include Lessons in your sideboard if you’re playing with cards that instruct you to learn, Lesson cards can be included in your main deck like other instant or sorcery cards.

Reduce to Memory : règles, fonctionnement et interactions (MTG)

Reduce to Memory is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Exile target nonland permanent. Its controller creates a 3/2 red and white Spirit creature token.

How it works : Reduce to Memory

Original English text — Wizards of the Coast / Scryfall

#1April 16, 2021· Wizards of the Coast
Lesson is a spell subtype found on some instant and sorcery cards in the Strixhaven set. The Lesson subtype has no special rules associated with it.
No other card is named in this ruling.
#2April 16, 2021· Wizards of the Coast
Although you may want to include Lessons in your sideboard if you’re playing with cards that instruct you to learn, Lesson cards can be included in your main deck like other instant or sorcery cards.
No other card is named in this ruling.