Things like exactly how much armor was on the front of a Panther D compared to the A and what reference books have it wrong. At the same time, we bickered, argued, talked, and cajoled each other about the very core of this title. It is, after all, a computer game, and there were just as many arguments about how it could be designed with an ease of use, a realistic but enjoyable model of tank warfare, and what gamers are going to expect when they try it out for the first time. Testing was, to put it mildly, a lot of fun for me. These aren't in any particular order, but I think they are the core of my schooling in product development.
Testing is hard work.
Maybe that's an obvious statement, but I think many people assume testers do what they do for the sake of getting their name in the credits or a free copy of the title when it's released. However, if you sign on to be a tester for the purpose of getting your name listed in the credits, you're a sick, sick person. There are some components of PE that I must have tried dozens of times, over and over and over. Testing means frequent uninstalls, reinstalls, changing configurations, remembering, recording, and repeating. It can be a real bear.