It’s an important thing to be mindful of when handling a deadly device and far too easy to become complacent if you don’t strive for 100% compliance.

It’s not wise to wipe your nose while holding a loaded gun with your finger on the trigger.

From The Three-Body Problem by Cixin Liu:

Later, other Adventists based their hatred of the human race on other foundations, not limited to issues such as the environment or warfare. Some raised their hatred to very abstract, philosophical levels. Unlike how they would be imagined later, most of them were realists, and did not place too much hope in the alien civilization they served either. Their betrayal was based only on their despair and hatred of the human race. Mike Evans gave the Adventists their motto: We don’t know what extraterrestrial civilization is like, but we know humanity.