Cory is apparently unaware of what the ending to "Romeo and Juliet" is. He should know already what happens as he studied it in Pilot (1993) where it was integral to the plot.
Cory says that Topanga pushed him up against his locker and gave him his first kiss when he was 13; however, in the episode in which this occurred, Cory's Alternative Friends (1993), he was 11.