"Aurora" was never released as a single and most casual fans don't know it, but the diehards feel it's one of the group's best. The band agrees. "It is definitely one of my favorite songs that we've ever come up with," Dave Grohl said. "Lyrically, it's just kind of a big question mark, but the words sound good and it's a nostalgic look back at Seattle and the life I once had. That song actually questions the meaning of life, probably. It's probably the heaviest thing I've ever written." The song has been a highlight of the group's concerts ever since it came out in 1999.