Yup.
Had one over 10 years ago. We'd known each other as coworkers but there was nothing at all but the "Hi, how are you?" type of interaction.
Somehow we drifted into being friends. A bit more time and I realized there was more going on beneath the surface.
By the time the light bulb came on there was a lot mutually unspoken between us just simmering, waiting for one of us to do something about it, I'd waited too long and someone else swept in from nowhere and she was gone.
She was funny, confident, intelligent all hidden away behind a California surfer-chick body to die for and a mop of blond hair. (she really was a surfer too
)
I doubt we would have lasted too long, but it would have been one hell of a ride while it did.
It did teach me to be absolutely up front about my feelings for someone as soon as I figure them out. To say how how you feel, what you want clearly, no games, no bullshit and being told "No" is far less painful than living with the "What if?" the rest of your life.
I still dream (and daydream) of her at least once a week