How do you know when you fall in love with a person?

He should be at work now.. Tues and Thurs is when he doesn't have gym and lesson.
Did he really didn't see the card? Or is he feigning ignorance?
If so, he didn't bother going to the blog to even take a look?
That's really sad then..
Doesn't even wana find out more about my feelings towards him? Am I being narcissistic? Is it that I'm so wrapped in my own thinking that I cannot understand and accept that he doesn't likes anything about me?
Am I twisting my own thots? To make me believe that this is a 2 way feeling? Cos i think way too much into his every actions? That I managed to convience myself that everything he said, wrote, mentioned and done before is actually a subtle hint that he likes me? And thus I sank deeper and deeper into this self created relationship?
Do I really like him? Or do I like the feeling that there's someone I can think about? How do you know when you fall in love with a person?