"Forever Young" embodies a "beachy" vibe, rooted in moombahton, with influences from reggaeton and balaeric beat. The song features Blackpink proclaiming "Blackpink is the revolution" in the lyrics, showcasing themes of self-confidence and empowerment. It's a track that feels like a declaration, even including English-language swear words, which was uncommon for K-pop girl groups at the time. This song from their first Korean extended play, Square Up, captures a vibrant and bold energy. Playing it can feel like stepping into a confident, celebratory moment.