No, I'm not talking about the subject in school -- I'm talking about person-to-person chemistry.
Let me explain a little bit about how I operate when it comes to dating... I'm generally a bit shy and timid person, and the fear of rejection and anticipation of an answer when you ask someone out is very intimidating for me. Therefore, I like to spend lots of time with people before I really ever make a move to make things official -- basically I play it safe so that I know whether or not things are going to work out. It certainly saves the pain of short relationships, because it never was a relationship in the first place.