The phrase comes from food reviewer Daym Drops, real name Daymon Patterson, whose 2012 Five Guys Burgers and Fries review went viral on YouTube. The Gregory Brothers turned his enthusiastic lines into an auto-tuned song called Oh My Dayum, which spread the clip far beyond the original review. Lines about the burger became a wider meme for exaggerated enjoyment, and the short hook survived as a standalone reaction sound shared across edits, remixes, and social posts.