The Winslow family and Steve Urkel act as if they've never met, even though Steve has been in their home several times via brief appearances in previous episodes.
Urkel said that he had passed by the cemetery on the way to pick Laura up for the dance. He is the next door neighbor how would he "pass by" a cemetery to get to the Winslows.
At the beginning of the program Laura says she wants to go to a dance as the program continues the word dance is constantly substituted with the word party.