This summer song was co-written by Tim Armstrong of the Punk-Rock band Rancid. Armstrong also plays guitar on the track. Walsh told Billboard magazine: "Tim's a great songwriter, and he's about 180 degrees different as you can get from me. But we got together, and I really liked that song. It was a demo, he was still writing it, and I helped him with it, and gradually we ended up finishing it. There's another girl he wrote it with named LP, a young kid who has written some songs for other people, and I have to recognize her. I YouTube'd her, and she's pretty darned brilliant. That song doesn't sound like all the other ones, that one sailed out in a different direction. It grew on me and I had to put it on the album, but I felt like I was really part of it."