As the politicians say, he works the room. A good guest doesn't say anything when you're given the same scented candle you gave your host last year. Besides, if their memory is that bad you can always wrap it up and give it back to them next year. Some parties are like being dropped behind enemy lines. As a guest you should be prepared by bringing a survival kit.
Some hosts are slow to offer a life-sustaining drink.
Rather than be a burden, wrap up a bottle of your favourite hooch and say it's a present for your next stop. If things get bad, say your imaginary friend will understand if you open it up. A good guest doesn't let a party get below critical mass. If it does, help your host deal with that last problem guest who has no intention of leaving. Lure them outside with an offer to drive them home, then claim your car has been towed.