Definitely Jerek, he's the one to overanalyze a situation and either do something stupid because of it or not do much at all. So many missed opportunities from when I was his age, so he's a bit of an escape from that. He's also definitely handling a changing paradigm much better than I did at that age, I felt (and still majorly feel) betrayed by organized religion when I was a teenager, and Jerek got a little of that as well, but is somehow managing to come back from that.
Jerek's also someone I can easily slip into most scenarios with ease, which was very much me as well. I just mostly rolled with the punches at that time in my life, I had my own goals and desires, but when things happened I tried to make the best of them. It makes it fun to put him in different scenarios and see what happens.
Most of my other characters are somewhat contrived or just responses to various ideas outside of myself. Jerek is much closer to me than others.
