First of all it must be said that the script is probabaly one of the best written in film history. Also, Casablanca is everywhere in pop culture. Also, Rick Blaine is symbolic of America before and at the beginning of WW 2 and so is the cafe. Casablanca itself is a purgatory that none can escape from. Furthermore, I have speculated that the line "Here's lookin at you, kid" means it's up to every person to do what they know is right and to change the world because an individual has that power. Casablanca is more than just a story of love between two people. It's a story of love for humanity.