i got this in my philo 4 book..
signs that a man is truly in love with the object of his affection:
1. he calls you up for no reason at all...
2. he talks about you with his friends...
3. he is pleasant to your friends..
4. he listens, listens and listens to you..
5. he is punctual on dates..
6. he does not belittle your interests..
7. he refrains from talking about previous girlfriends(if there are)..
8.he does not force you to sleep with him, reasoning out that this is the test of you love for him..
9. he makes and keeps actual dates..
10. he is not afraid to reveal his true feelings to you..
as for me.. i like this one by thomas middleton:
love is all in fire, and yet it is ever freezing;
love is much in winning, yet it is more in loosing;
love is ever sick and yet it never dies;
love is ever true and yet it is never lying;
love does not dote in liking and is mad in loathing;
love indeed is anything, yet indeed is nothing..

When all else fails..don't stop.