When a girl is really into you, she may find it difficult to think about anything else. She wants to talk with her friends about you; she wants to listen to music that reminds her of you; she may even watch movies that seem to mimic the love-sick scenario she's in.
But during class, there isn't any way to express the emotion that's bubbling up inside besides inconspicuously writing your name or initials on her notebook, textbook or even her hand. If your name is John Doe and "J.D." is unmistakably appearing on her class notes, you're in [source: Kirkberger]. It's a classic tell-tale sign. It can't be denied. Unless, of course, her name is Jill Davis, the school quarterback is Jim Dawson or her class is reading "The Catcher in the Rye."