Yea loads of times...I am quite easily smitten.. unfortunately I tended to get smitten by the wrong ones, and the ones who wanted me to be smitten by just weren't my thing.. I've not been smitten in a good long while.. I am trying hard to avoid that now :P
Once - a mind-blowing, life-changing experience. A couple of other times briefly, not so intensely. Feels like the best drug on earth while under the effects, but the after-shock in recovering from the delusions acts like a vaccination. Now I avoid infatuation and its relatives like they are poisons.
I embrace love when it's real: when the honesty, respect, trust, empathy, caring, intimacy, and openness of two whole people is complete. Anything less is not worth the time invested.