ND Negligent Discharge. It does not just happen to new people. It happens to seasoned veterans also. Cold, tired, irritated, rushed, worried, sick, and a thousand other reasons. 20 years ago, I purchased a $15 insurance policy, insuring I should never have a ND. I am already careful. Muzzle in a safe direction, finger off the trigger until ready to shoot, ammo and guns in two separate locations, until ready to use the gun. I practice, drill, meditate, ponder, and hope for good karma. But just in case, all my Glocks, have a Trigger Block Safety, inside a level II Serpa. In this condition, I personally feel safe, and responsible, as well as ready. Before anyone follows my personal rule, don't follow me, unless you train with me. Also, read your owners manual. Glock owners, Glock does not recommend one in the chamber outside law enforcement or military. Many other gun makers advise the same.