The song "400 Trillion" by Justin Jesso is about how rare and unlikely it is for two people to meet and fall in love. The lyrics describe the odds of our hearts even beating, let alone meeting someone special, being one in four hundred trillion. The singer reflects on how meeting his partner has changed his perspective on life and the things that matter. He no longer takes anything for granted and values every moment he has with his loved one. The song is ultimately a celebration of the power of love and the profound impact it can have on our lives. Despite the odds being against us, the singer believes that somehow he and his partner were meant to meet and be together. The song serves as a reminder to cherish the people we love and to never take them for granted. Overall, "400 Trillion" is a heartfelt and romantic song that encourages listeners to appreciate the rare and precious gift of finding true love.