Probably should not admit to it as I am not a rookie, but,,
How about backing your sled down the ramp in front of about 10 other guys waiting to launch, unhook the boat, then decide to re-position the boat, pull forwaed and dump the sled on the ramp only to listen to those 10 laugh so hard they almost wet themselves.

Standing on the edge on a big rock, set the hook only to slip off the rock in about 10 feet of water and fill those old rubber waders to the top, no belt of course!

Telling your new fishing buddy to get up on the bow of your sled to put the 65 lb. anchor in the bow cleat at an idle only to hit a stump and dump him in the river in December.

Watching your buddy on the Skagit swing full power to wack a fish only to hit his new graphite rod (sitting on the seats) on the way down blowing it into about 5 pieces. Did hit the fish after the rod. Man did his day go bad after that, 18 foot sled and 3 guys razing you for 6 more hours.