How do you know?

So after a short discussion with my boss, who told me that I was wrong about knowing what love is... I have decided to research this subject and decide... "How do you know you are in love?"

A co-worker is going through a divorce and since we are all pretty close, we are trying to give him some advice. My boss doesn't believe that what my co-worker feels for his soon-to-be ex wife is love. If it wasn't love, why would he continue to be with her for 7 years? Maybe I am just old fashioned and believe that love never stops... it can change... but it never stops. And I don't believe you can only fall in love once... but I do believe you have only one true love.

I have only one real experience of breaking up. I had a few "boyfriends" during my time, but before my husband, I was only in love once. And when we broke up... and the months that led up to our breakup was earth shattering. I really loved him, but he never loved me. There was a lot of time and energy that was put into our relationship, but I was really just someone to pass the time with. Knowing this, never made it easier to forget him or to stop loving him. A certain song would come on, or something was said, or a car like his would drive by and I would lose it. And only time made it easier to get through the days without him. It doesn't matter that he broke me heart and lied to me, it would not have made it any easier had he just told me that it wasn't working out. I honestly, hopelessly, completely loved him. And to an extent, still do today. I don't wish bad things on him. I wish him happiness and a good life. And if we ever meet on the street again, I will smile and be thankful for all he taught me. He taught me that true love is a lot different than anything I had ever felt. So when I met my husband for the first time, and we fell in love...

I knew this was it. This was the man I was going to spending the rest of my life with. I think I knew after our first fight, and the first tear fell, and I didn't want to be mad anymore... I just wanted to curl up into his arms and stay there forever. He became my comforter, my best friend, my confident. I knew I wouldn't be completely without this man. And trust me, we've had enough bumps in the road to make sure we would work. I can't imagine my life without him.

How did you know you were in love? Have you been in love more than once? Is that possible? I want to know. Here is what I have found so far:

Wikianswers.com "if you ask, you either doubt your feelings, in which case you aren't truly in love, or you don't know if the relationship will/would work out, which is an altogether different question, since being truly in love isn't enough for a successful relationship, though it's a good start, especially if by "you" you mean "both of you".

yahoo.com "i doubt anybody can really explain this no matter how detailed it is, and how hard they try. i asked my friend this question the other day and he said that just because your passionate about someone, or you love them, doesn't mean you are in love with them. People usually say that being in love means you want to spend the rest of your life with that person, but if you think you can spending the rest of your life with them. I doubt it is really love. You've got to find someone you can't live without :)"

beliefnet.com "Being in love is an altered state. Suddenly your life is focused on another person and you can't bear being separated from him or her. You are in a bubble of fantasy, feeling overcome and giddy. Love for another person, in contrast, is closer to appreciation and affection. Love is fairly reasonable, while being in love is more like a prolonged seizure, not literally sick or crazy, but one of those ordinary, positive ecstasies that take you out of ordinary life and introduce you to something new."

I wanna know what you think love is...