1.  Most of my problems here have stemmed more form not being in the same rhythm as the other American students.  Intercultural understanding is almost easier when it's pushed along by lack of pre-existing friends from the United States.  What I most had to work on it  learning to travel, enjoy myself and stay safe alone instead of trying to go do things with people who have different goals and expectations about this trip and having a good time.
2.  In the first week, I felt very shy, confused and like an outsider.  People tell me I'm not shy probably because I would invite myself along excursions with other United States students (or at least try to) even if I knew that they were going to pursue a more intense manifestation of "fun" than I enjoy.  I felt like I was the awkward outsider in middle school again.
3.  Now I'm getting comfortable planning independent travel and the United States students know me better and accept that I'm not a big partier and I have a better idea of who I want to spend time with.  I'm more comfortable talking with Spaniards that I meet on the bus street etc, now too.
4.  I gained a lot more confidence in my ability to speak and understand Spanish (from practicing speaking with host family)  This confidence probably made me even more understandable and probably made me seem like less of a target for ill-intentioned locals.  Asking questions and repeating the answers back to the person will almost always get you the correct information.
5.  I'm becoming more self confident about my ability to express myself and my personal control over my situation (i.e. internal focus of control)  I also nurtured my sense of optimism (if I didn't I'd always be worried and never relax and enjoy myself)  Because I don't have other people to plan fun for me or try to please I've been learning how much activity and fun seeking I can realistically expect from myself.
6.  When I get back, I'll probably be a lot more self confident in my dealings with other people (business school friends) and if I'm not a loner I'll be more of a leader.