Job interview !

This is the third time its happening to me.
Whenever you don't care about your interview it goes well, but when you care about it you're gonna mess it up.
Today was one of those days that I really didn't care about the interview, not that I didn't like the job, but I was in reserve list from the begining and they were not really looking for a PhD. So, I just showed up to chat.
Not an answer yet, but it went well.