No, I haven't, actually. Which I'm happy for.
I mean, I've had my fair share of let downs. I had a huge crush on this one girl, and I guess I still sort of like her. I made a big deal about her recently. I wasn't heartbroken when I asked her out and got a rejection, though. In fact... I kind of felt a little happy. I guess I was happy that I had it in me to admit it. And we're still best friends. =]
So no, I haven't had to feel heartbreak. Hopefully it stays that way for a long time to come.