Just a little background, I'm a 25 year old in my first year of medical school. I've been in school for roughly 6 weeks now.

I've noticed a general pattern emerging in my interactions with most women. I don't show any interest, they become interested (grabbing my hand, inviting me to hang out, messaging me to talk about 'nothing' on facebook), and then I reciprocate my interest, and eventually lose theirs. Its a strange phenomenon and very frustrating.

For example, my most recent frustration includes a girl in my class. She was my beer pong partner at a tournament, then she asked me to study with her, then she invited herself to my room last night to study, but then dismissed herself when I suggested we relax for a bit before calling it a night. On the way out though, she asked the guy living across the hall (we're all mutual friends) if he wanted to go chill out on the dock...what?

Anyone have thoughts on this particular situation, and more generally how to not lose interest when I reciprocate my own?