What's the most agonizingly painful thing that you have ever had to live through?
List more than one case if you like, and definitely cases that you have at least witnessed.
I remember (vividly of course) several years ago when we were building the treehouse, my dad was screwing in the gigantic base-boards for the platform to be built on top of... He screwed in one end already, but when he went to get the other end, he forgot to screw it in and let go. It swung down, and guess who was right at the bottom when it was swinging the fastest? Me.
It hit me in the crotch with more punch than anything I have ever felt in my entire life - enough to actually send me flying. I'm not even kidding.