Unless I'm about to shoot the gun, I practically have an OC (obsessive complusive) disorder about ensuring a gun I have in my hands is unloaded. If the cylinder is closed, I'll open and look at each chamber. If the action is closed, I'll open it and check the chamber. And it doesn't matter if I just took the rounds out of the gun and set them on the table in front of me, if I close the cylinder, slide, or bolt, I check again.
I learned a lot time ago flying jets in the Navy about the problems associated with broken habit patterns. If I'm not going to shoot it, I always follow the same habit pattern. All it takes is one time being lazy, inattentive, distracted, whatever it takes to break the habit and you or someone near you may not live to regret it.