Fine line between controlling and being controlled

A few weeks ago, I applied for this position at the Elitist Research Institution and hadn't heard from them since. It wasn't a big deal for me, because I didn't really fit the job, but it had helped me feel better about my present position, giving me the impression that IF I REALLY WANTED IT, I could get another job and leave this place (So there! nanananana!) - so I felt in control (and hardly childish at all). It made me feel more comfortable at work, and eventually I reached the Level of Neutrality again when thinking about it.
As I was eating with a fellow student at the uni-restaurant today, a call came through on the mobile I still have. I was going to cancel it, as I've never liked it when people I'm talking with suddenly give all their attention to a phone. But I didn't recognise the number, so I apologised to Fellow Student and answered.
It turned out to be the Hiring Woman for the position I'd applied for. She sounded very nice and asked me to come over for an interview. We made an appointment for next Thursday, and that was the end of the conversation. As I put the phone down, I looked at Fellow Student, who had guessed it was about a job interview - and I didn't know what to think or how to react anymore. She seemed more excited about it than me. I had totally forgotten this application and felt taken aback, unprepared. Even uninterested. The surprise is so great that I feel I've lost control once again.
What if I end up getting the job? Taking it is a risk of sorts - possibly less money, unless I manage to make my case for a higher salary, and less security, as the contract is only for one year. But also: a different working environment, different methods and techniques, more contacts and in any case something nice to put on my CV if I change my mind about hating urban elites.
Me puzzled.