Half of the jokes in Big Lebowski are just the dude parroting a line he heard earlier in the day but in an absurd context or conveniently using the same odd dialogue from multiple characters. 

Ex. - he overhears Bush Sr. about how aggression will not stand in Iraq on the news in the opening sequence, he brings it up later (I think?) when first confronting the other Lebowski about the rug. 

Or, the dude initially calls the carpet pisser a Chinaman, Walter makes a big deal about it not being the proper nomenclature. You kinda forget about it until the next scene when Lebowski goes off on his rant,

“You think I was born without the use of my legs? No! Some Chinaman took them from me in Korea!”