It's an interesting topic for discussion (which I'll bow out of right now because I need to get to sleep). Several of us on HP, including me, have written Hubs about it. I think there are some poems about it here too. It might be interesting to look at some of them and then to compare notes from different perspectives on the subject.
Oooh I love this question!! Well first let me say that I have a 7 year old old girl who swears that she is in love and even decided that she didn't want to be friends with this girl because the girl was standing to close to this boy....obviously she is too young to even be thinking in those terms. Witht hat being said, there were many times as a teenager that I swore to my parents that I was in love, and I always heard the same thing...."You don't know what love is!" So being the analytical person that I am, I spent a lot of time trying to pinpoint my feelings to the point where I knew I had fallen in love, and this is what I have come up with: First off, you get to the point where the other person is all you can think about, you go out of your way to find reasons to call them, run into them in random places, and learn their intersets and adopt some of them as your own....but remember, there is a fine line between loving someone and stalking them Ultimatly though, I think that when you get to the point where you cannot imagine your life without them is when you know you have fallen in love. It really is a great feeling but it can be the most devestating thing one can experiance also. Heartbreak is never fun, but I think it's how we learn the greatest lessons in life.
This is a true story. I had a workmate in the late 70's who was in a punk rock band. Remembers those feelings, when your stomach is doing somersualts when you see that girl/boy you are sure you are in love with.
Honestly, he wrote a song called "I thought I loved you but I only needed a shit"