I'll start:
The dumbest/funniest thing we did in our first season was manage to completely "dry dock" ourselves while camping below Hoover Dam. We knew the water fluctuated a bit throughout the day, but had no idea that it would drop by several feet during the night. We woke up completely dry, and it was to the vast amusement of everyone who passed that morning on the very busy stretch of water. Lots of people stopped to investigate, offer help, and laugh. A nice group of kayakers, about 30 of them, stopped and helped us lift/pull the boat off the beach a little before noon. Here's my wife giving it a valiant solo effort. My favorite part of this picture is the anchor that was under 2 feet of water when we fell asleep the night before. (We use a bow and stern anchors now too.)

We did plenty of scary things. Two trips to the ER, one when I sliced my foot open on the prop while floating behind the anchored boat. The other when when my son slipped while hiking up to the hot springs and gashed his head open. I'm not going to post pics of those, but both were bad. Good thing we always have a stocked first aid kit. The park service folks at the boat launch were a class act too, very helpful when we docked. The biggest thing I learned from these incidents is that I need to make sure my co-pilot (wife) is 100% familiar with everything, including backing up the trailer.