In general, honesty is the best policy. If you really were influenced to great things by HJPEV, explain it well and it should go over well. If the admissions folks are going to say "This well-written and inspiring essay is about fanfiction" and thus throw it in the garbage, it could just as well have been thrown away for the room's lighting or what they had for breakfast.
If you really were influenced to great things by HJPEV, explain it well and it should go over well.
This is important. Deliberately choosing to write about fanfiction is a high-risk move, and so is high-status if you pull it off well! But you might just face-plant. (You don't try out unpracticed tricks in front of a girl you want to impress.)
Or to put it another way:
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
If continuing the discussion becomes impractical, that means you win at open threads; a celebratory top-level post on the topic is traditional.