This is what I was told when I started work. If you make a mistake, just admit to it. They most likely won't punish you for it if it wasn't out of pure negligence

It's difficult because you have a 50/50 of having a manager that doesn't respect mistakes and will immediately get you fired for it (to the best of their abilities), versus one that considers such a mistake to be very expensive training.

I simply can't blame people for self-defense. I interned at a 'non-profit' where there had apparently been a revolving door of employees being fired for making entirely reasonable mistakes and looking back at it a dozen years later, it's no surprise that nobody was getting anything done in that environment.

Exactly!