Why's he sad?

I was leaving for work the other day and I had Lightning Rod by Guster stuck in my head, so I popped it on before I left. Audrey was listening and asked Jennie "why's he sad?" The girl is amazingly perceptive – she obviously doesn’t know what the guy is singing about, but it “sounds” sad. So she sat with Jennie and decided why he was sad – his friends left him behind, he had owies and needed a band-aid, etc.