LOL! I know that feeling, though these days we have a Christmas box for cards and paper that we put in the loft out of the way. Since doing that, we don't lose so many January sales items - but occasionally something will still manage to disappear into apparently thin air, only to turn up mid-year!!!
Sometimes I think there's a black hole collecting odd socks, pens, Christmas cards etc - and occasionally it reverses and spits a few back out!!! *bg*
And now cue a Rodney rant at my lack of basic black hole physics...!!!