Love .. Mystery

"I am falling in love with You", this is how generally we express our feelings for other one. that's what i have seen happening around me here. But then i always wonder, is it really love? or any other emotion. As per what i know about love is that, it is divine and the most purest emotions of human kind. Then how can one fall for it, this can be called as "i am rising in Love with you". We can only rise in love and not fall. I just wanted to talk about love and not english here. My point is when we say this, is this really love?

Most of the times it happens that some person comes in our life when we were sad and needs a shoulder to cry, and we get along with that person. And then matter of few days we jumps to the conclusion that, he/she supported me whenever i was down, he/she's the one. he/she's my emotional support. But then does it mean that, if you were not sad, this whole love thing would not have happened?? To experience love does everyone has to go thru some depression level?? why cant we find love when we are happy.

I just don't understand what makes people conclude that they are in love, i have asked so many people about it and all of them gave me same answer, ""U'll get to know yourself when you will experience it"". But then no one actually answered the question. Is there really no answer to it or is it that hard to define it?