The original idea for the song came to guitarist / primary songwriter JB Brubaker when he was driving to his sister's house to meet her and his brother in law for dinner. He recalled to AntiMusic
: "I was listening to The Hope Conspiracy's album Death Knows Your Name
and thinking how cool it'd be to play in a band like that. The thought of writing straight forward driving hardcore songs was very appealing to me and I began to think about trying to write a few of my own, not for ABR, but on the side. I never really had time to do a side project, and as it would turn out, I still didn't."
When Brubaker got home that night he began fooling around on his guitar trying to write something more in the vain of The Hope Conspiracy. He told Anti Music: "I wrote the main chord progression for the song and the big build up intro. Being that everything was fairly straightforward the song was coming together very quickly, that is until I got side tracked when I saw my glass guitar slide sitting on my desk in front of me. I have never been very good at playing with a slide, but always thought they sounded cool so I occasionally would play around with one. While noodling about with the slide I came up with the melody to the clean section in the middle of 'Carpe Diem.' It was a simple slide part that kept me on only one string, which was difficult enough for me."
Brubaker got himself back on track working on the song he had set out to write in the first place, but he couldn't get the slide guitar melody out of his head so he decided to try to work it into the tune he had been writing. Once he'd finished it Brubaker sent it to his bandmates, but was somewhat wary of what they might think, as it was so out of the ordinary for ABR. He recalled to AntiMusic: "I emailed it to everyone and explained how I loved the song, but realized that it was very different for us and if everyone hated it, I'd just save it to record on my own time down the road. Everybody was cool with it except for our bass player, Dustin, which is now ironic because he is very fond of the track now that it's all finished and recorded."