Manual files never surprise you" is a wild thing to say. My old rasp pinched my thumb more than once, that was a surprise I didn't need. Caleb826 has a point about speed, but gentle is the key word there. If a tool spooks your horse, it's not the right tool, full stop. You gotta know your animal and what they can handle.

Totally agree. That kid's paper method is how I finally got my head around recursion.

A whole stack of them? How long were they in your garage before they went bad?

Did you see the video of that guy's brick fire pit washing down the street? It reminds me of what happened to @taylor492. The water just gets under everything and lifts it like a raft. Proper ground prep is no joke.

That pink color is usually a sign of yeast. Did you use enough salt to keep the bad stuff out while it fermented?