My neighbor had the same problem and went with epoxy paint on the concrete floor. It looks like a garage floor now, but it's bone dry. I still prefer the feel of something underfoot.

Polarizing filters are great, but sometimes the noise is the point, @the_nathan.

Man, that's the absolute worst feeling. I've done that exact thing with my K1000 before, shot a whole wedding for a friend and got nothing but blank film back. In a loud place now, I always close my eyes and feel the rewind knob turn when I advance the first two shots. If it spins, you're good. Sorry about your kid's first fair, that's a real gut punch.