Must've been when I coded something of the core module of a game... into and with the test interface.
I was reminded that by my colleague who initially made this and spent a huge ton of time more than anyone else on the project. I felt a bit powerless while trying to assist in that, but I also felt bad about that error of mine.

...

That or that time when I set my whole system to protected and read-only during a system programming exercise because it ran out of memory real fast.