The first rule is the most changed and debated. You probably don’t like this rule because it is factually wrong. A gun CAN be unloaded. Most change the rule into “treat all guns as loaded” or something similar. The reason I like the wording: “All guns are always loaded.” Is because it is wrong and it bugs me every time I read, hear, or say it forcing me to think and not get complacent. The statement “All guns are always loaded” is a statement of belief, not a statement of fact. You need to believe this is the case so that you only have one way of handling guns.
The problem with “treating” guns as loaded is that many establish two sets of handling procedures, one for “dangerous” loaded guns and a separate set of procedures for “safe” unloaded guns. Inevitably, you will make a mistake because having two sets of handling procedures requires you to always know if the gun is “dangerous” or “safe.” The safe handling of the gun is still dependent on your belief. What happens when you are wrong? The answer is you will make a news headline. What is the quote in the typical news story when someone negligently kills his friend of family member? “I thought the gun was unloaded.” What was likely said before the person in the catastrophic news story performed his negligent act? “Don’t worry it is not loaded.” If all guns are always loaded, then this is never an option and negligent gun handling is never a problem.
Of course there is usually not a problem when we are keenly focused on how we handle guns (.i.e in the classroom or on the range). The problem occurs in the practical application of life. When you are cold, tired, hungry, and distracted with many other more complex problems, that is the time when you fail to know the condition of your weapon. If you choose to maintain a system that is reliant upon your intelligence and focus. It will eventually fail you.
Be humble and embrace a system of gun handling that is not reliant on your focus and intelligence.