It comes from the fact that you haven't realised how much sexuality a girl has and haven't been able to extract it from this particular girl at all.
Let me break down how uni works in general, its just like high school but with alot more freedom, the jocks still rule and the nerds still get put down, learn to distinguish between what is real and what is fake, girls at uni are there to find out who they are in life, thats why they do weird as degrees and papers.
Now the real reason why you don't ever say its a date its because you already asked her out to the movie she already knows shes going to go with you to a movie she doesn't need to be told that its a date, she knows its a date but would rather play along and get swept off her feet.
They must have a paper that teaches you about how humans socialise and how the human mind works, my advice take it it'll teach you alot.
They aren't easy as in go grab a girl and take her to your place and shag all night long, theres an art to the process which has been programmed into you from birth, you just need to learn a few things about it to get it working for you.
Now my advice this so called girl would be to ditch the movies idea and take her for lunch to a nearby park get in close talk about any crap you want just not boring things about studies ........ actually don't even mentions anything to do with studies isolate her get close and go in for a kiss. Try it if it works good job if not look around plenty more.