Forget 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

Target player discards two cards, then draws as many cards as they discarded this way.

How it works : Forget

Original English text — Wizards of the Coast / Scryfall

No additional ruling has been published for this card.

Interactions with other cards

These cards' text mentions Forget.

Lulu, Forgetful Hollyphant

Flying Specialize {2} When Lulu, Forgetful Hollyphant enters, you get a one-time boon with "When you cast a creature spell without flying, it perpetually gains flying."