 "Once" tells the tale of a man's descent into madness which leads him into becoming a serial killer.During the bridge of the song, Vedder can be heard muttering.He is actually saying "You think I got my eyes closed/But I'm lookin' at you the whole fuckin' time..."

Stephen M. Deusner of Pitchfork Media said, "On songs like 'Once', with its insistent breakdowns...there's a hardscrabble dynamic that the band would be unable to capture on subsequent releases."