When you fall from a height(or have that sensation in a roller coaster) it feels like your stomach comes up into your throat. Falling in love has a similar sensation.:-)

I think of "falling in love" as being swept away, as others have, or a hopeless infatuation (which is definitely not love.) I didn't "fall" in love with my wife. I met her, I loved her. I used to kid her that there'd be plenty of time to get to know each other after we got married. Love came first, then knowledge. One of these days, I'm going to take her out on our first date. :-)

Jerry