1.talk worldly affairs freely;
2.know nothing about what is going on in the world
4.Time flies by, and a world of changes has occurred.
5.Yes, it can happen so quickly.
6.Nothing is certain but uncertain.
7.He is dead to the world.
8.World aflairs are ao changeable as the weather-cock.
9.Nothing so sure as death.
10.take a mournful view of human affairs