Swim by Jack's Mannequin is a song about perseverance, resilience, and overcoming adversity. The key themes include facing challenges head-on, not succumbing to difficulties, and finding the strength within oneself to keep going. Particularly poignant moments in the song include the recurring metaphor of swimming as a means to stay afloat amidst life's struggles, symbolizing the effort to remain strong and determined no matter how overwhelming circumstances might be.