It happens. Also here's an appropriate song that came to mind

http://youtu.be/2QnFRtfVqUs

Yes and it usually does not end well..

Good advice from Zac and the boys with AJ

"Don't Be Falling In Love, As She Is Walking Away"

I've  ignored that advice like X4 in 8 years---about every 2 years---not due until next year)
Or, sooner, if I run into one of those "Big eyed girls" the Big Bopper sand about)

But that is not the same thing as "being" in love.
One must never step over the boundaries.