...Must Come to an End (2) - S6-E24
Trivia: The video montage Pacey shows Jen is to the tunes of Alanis Morrisette's "One Hand In My Pocket". The producers for "Dawson's Creek" originally wanted this song to play in the opening credits for the show but Morrisette said no.
...Must Come to an End (2) - S6-E24
Trivia: The scene towards the end, where Joey and Pacey are watching "The Creek" from her NYC apartment, was the actual last scene shot for the entire Series. Also during that scene, when Pacey is shown crying while watching "The Creek"; those were actual tears from shooting the very last scene of the entire Series. Joshua Jackson was really crying, not just acting. (01:41:10)
Answer: It's only explained once in the series. Jack says to Andie "I tried to start kindergarten without you", meaning Andie was smart enough to start school early.