I'm still carrying the scars from a spill off a cousins boat. It was setup for ski racing, so would only go really really fast (or that was the storyy). Anyway christmas afternoon, after a long lunch, was towed on the biscuit (really really fast), flicked out on a sharp turn over the wake, shot 10 ft into the air, landed with my forehead on my knee and spent Xmas evening getting my forehead stitched up.
And of course its the most junior Dr who gets to do the christmas evening shift...
That was a boxing day headache not easily forgotten.
So I tend now to be a bit careful with my passengers!