I've never been hit by a ball, but I did hit an elderly gentleman once, and a bird on another occasion.
I was with a group of friends playing at Hyland Hills golf course in Westminster, CO. Truth be told, we were a bit inebriated. Not stinking drunk, mind you, but we'd had a few (I'm sure the folks on this site are too classy to have ever done this, but there it is).
On a short, uphill par 4 there was a pond directly in front of the tee box. Not in play, really, unless you just couldn't get off the tee at all, and on that day, on that hole, my friend Mario was unable to hit a ball over it. He proceeded to splash 4 or five in a row, which generated a lot of amusement amongst his playing partners.
I had to step to the tee after him, and proceeded to find that hitting a ball while highly amused is a difficult thing to do. Rather than hit it in the drink, I managed to hit the ball off the toe of my driver, with a trajectory about 90 degrees to the right of my intended target line. The ball bounced down a cartpath directly towards an older fellow trudging up the hill dragging his pullcart behind him. My friends and I repeatedly screamed "fore!" as loudly as possible, but he didn't hear us, and continued to plod towards the green. The bouncing ball caught him directly in the crotch, and it looked to have stunned him briefly, and he stood there for a moment, wavering. Then, without further ado, he continued to walk stoically up the hill.
I'm sorry to say that, once it seemed that he was all right, my friends and I collapsed with laughter on the tee. The older fellow didn't seem to notice.
And no, there wasn't anyone waiting behind us while we laughed.........
As to the bird, I hit an approach shot on a course up in Boulder called Lake Valley, and a bunch of birds that had been hanging out in a nearby tree decided to choose that moment to take off. My ball caught one with a sort of soft thudding sound, and the bird fell as if poleaxed. It just took him a moment to recover, though, and he flew off after his brethren.
I know that on the whole this isn't a funny subject, but my only two experiences with it kind of were. Funny, I mean.