The day the earth stood still — AKA December 17, 2012, when Gossip Girl’s identity was revealed as the whole show came tumbling to a stop — is one we’ve mainly blocked out of our heads, with a little help from our dear friend Xanax. But just as we were shocked when Dan (Penn Badgley) was revealed as GG (if this is a spoiler for you, you are tragically behind the...