Lyric discussion by kozmik 

Cover art for 20th Century Towers lyrics by Death Cab for Cutie

Instead of following logic and reason, the choice to remain with someone (" i know the conscious choice was crystal clear") was the correct one. The song is about two things at least, but one of them is moving on from an old relationship ("to clear the slate of former years") and finding love somewhere else ("when i sang softly in your ear and tied these arms around you"). Or maybe it's about Jesus. Good song either way.