I think what it means is that once you have reached enlightenment, the only thing that has changed about you is inside of you. Outside is still the same. Even if you have found true, inner peace, there are still things to be done. You have just come to be more accepting of the world around you, and take them as they come. As my friends down in Florida, who are Buddhists, always say, take life one thing at a time, one day at a time; just keep on keeping on. Big Mac's constant "Eeeyup" is true zen. He accepts things as they come, and just keeps on doing what he knows has to be done.