How we cite our quotes: All quotations are from Casablanca.
Quote #1
RENAULT: I have often speculated on why you don't return to America. […] I like to think you killed a man. It's the romantic in me.
Everyone in Casablanca is trying to get to America, but Rick, an American, is here. We're never told explicitly why Rick can't return to America, but here's where we first get a sense that perhaps he would if he was allowed to. Rick may have gone from an American in Paris to an American in Casablanca, but he'll always be an American, first and foremost.
Quote #2
RENAULT: In 1935 you ran guns to Ethiopia. In 1936, you fought in Spain on the Loyalists' side.
RICK: And got well paid for it on both occasions.
RENAULT: The winning side would have paid you much better.
Rick tries to explain away his actions by claiming to have done it for the money, but Renault immediately pokes a hole in his story. It's true—if Rick was really only interested in turning a profit, there were better ways he could have gone about it. And since he's proven himself as such a brilliant businessman, it seems unlikely he didn't realize that at the time. You can't put a price on honor, eh Ricky?
Quote #3
LASZLO: I'm sure you'll excuse me if I am not gracious, but you see, Major Strasser, I'm a Czechoslovakian.
This is about the most gracious way you can tell a person you aren't being gracious. Polite and dignified as always, Laszlo lets Strasser know right off the bat that he doesn't intend to put on a false front and be all peaches and cream to the Nazi officer. Czechoslovakia was one of the first countries invaded and occupied by the Nazis. Laszlo has too much pride in his home country not to take this chance to drive in the stake a bit.