Lyric discussion by foto 

Cover art for We Laugh Indoors lyrics by Death Cab for Cutie

I love this song. To me he is saying he fell for the wrong girl. "I've always fallen fast with too much trust in the promise that no one's ever been here." He's saying that is one of the qualities he looks for in girls, but I think with Guenivere he was tricked. She might have let on that she was leading him into a territory where no one had ever been, but it was all a lie. Someone had been there before, and the territory he was led into was not pure, and he wanted pure. He wanted it and didn't get it. To top it all off, we better not get him started because he has more to say on the subject, but he wants to leave us on this level for now...