I am a 64 year old amateur historian and retired lawyer (patent law if anyone is interested, not that they are).
What is a retiree like me doing reading fanfiction? Simple, keeping up with the grandkids. My oldest introduced me to fanfiction a couple of years ago, and given my insatiable appetite for reading, I couldn't stop. Half the time I rely on wikipedia to sort out what the fandom is, and usually its the fandom that leads me to the original work not the other way around. Helps me sort through the crap that is mostly on the net. If I like your story without knowing the fandom, then it means that it can stand on its own as writing.
In any case, I've finally set up myself with an account. So I can hopefully get responses from the authors who I review.
As you can tell by my name, I am a particularly interested in the life of Erwin Rommel, one of the few people in the German army who wasn't a bastard.
Out of the fandoms I read, I've noticed several are videogames, rather ironic, considering I don't actually play them.