What is a good beginning for a book?

Pose a question; introduce a character; set a scene; lure them in with enticing prose; lay a clue to the direction the novel is going to take; plant the seeds of an idea; create a dramatic impression; give them a taste of action.

What is the opening line of Catch 22?

It was love at first sight. The first time Yossarian saw the chaplain he fell madly in love with him. Yossarian was in the hospital with a pain in his liver that fell just short of being jaundice.