Why does Buffy remain fresh after so long?

There�s a portrait of Buffy inside our house that gets older and older and older and less energetic and more tired while she stays vigorous. I think it has to do with a Faustian bargain. No. (Laughs).

She grows up. She�s a character who changes and who goes through things and that�s what blows my mind. You read Dag or Blondie or whatever - these are American comic strips - or Andy Capp for instance. They stay the same and that�s interesting for a while, but eventually you get the same beats, the same jokes.

[Buffy] continues, characters grow up, characters get ill and characters go away. They graduate from High School, they graduate from college and they go to grad school and whatever happens to them happens. I think that�s what keeps it fresh, because it�s like real life.