don't think they are just two balls ,they are two kinds of soul. Greater love has no man than this--that he will lay down his life for a friend. the red one give her part to the blue one.and also she gave her life too. wish the blue ball will go on his journey and get the guts to walk away from an unhappy situation True love is akin to a journey, so we shall carefully taste the epiphanic meaning manifested in each trip