Corrected entry: After they are flushed from MIB HQ, J begins to tell the story of how K used to love to be flushed. In the first movie, just before K hands J the Neurolizer, he says 'not bad for your first day, huh?" They were never flushed in the first movie.
Knapper
15th Jan 2011
Correction: Congratulations, you got the joke without realizing it was a joke. J is trying to keep K from getting upset about being flushed by attempting to convince him that he used to love it, figuring K won't know he's being lied to since he doesn't remember anyway.
Phixius ★