You constantly give each other gifts and try to remember who has which gift in front of them at all times. Memorising 2 objects seems easy? However, as soon as you memorise it, you have already forgotten it... and here you are with a cumbersome gift on your hands.
If you are not sure of the object in front of you, it is up to you to bluff convincingly enough to pass the unknown object to another player.

The latter can either believe you and accept your gift, or refuse it by saying that you are lying... at the risk of being wrong and getting a negative point!
A memory game... or at least where you have to pretend to have one. Simple, surprising and... simply unforgettable.