

There’s a jump instruction by an address read from RAM, a bit flip occurred so a condition “if friend greet else kill” worked as “if friend rape else kill”. Absolutely anything can happen, that wasn’t determined by program design flaws and errors. A digital computer is a deterministic system (sometimes there are intentional non-deterministic elements like analog-based RNGs), this is non-deterministic random changes of the state.
In concrete terms - things break without reason. A perfect program with no bugs, if such exists, will do random wrong things if bit flips occur. Clear enough?
You can’s speak about not having frequent corruption of files when you are not using tools detecting it. I can guarantee you have plenty of already corrupt stuff on your hard drives. RAM bit flips do contribute to that.
You have bugs (leading to broken documents, something failing, freezes, crashes) in applications you use and part of them is not due to developer’s error, but due to uncorrected memory errors.
If you’d try using a filesystem like ZFS with checksumming and regular rescans, you’d see detected errors very often. Probably not corrected, because you’d not use mirroring to save space, dummy.
And if you were using ECC, you’d see messages about corrected memory errors in dmesg often enough.