To this day, what surprises me most is that my computer was able to successfully boot and behave normally for an hour or two, even though random bits were apparently being flipped.

Yup. I once had a machine that would freeze up when I ran package updates. I thought (of course), that the package manager had a bug. Turned out, running the upgrade was the only thing memory-intensive enough to use the faulty memory that I'd installed. After all, on a light system you can totally boot and run in <1GB of RAM...