It’s nighttime. You awake to a noise outside. Is it a prowler? You aren’t sure. You grab a small pistol from your nightstand and shove it in your pocket as you proceed out to your driveway to investigate the disturbance. If it’s nothing, you reason, you don’t want to be walking around in plain view with a gun in your hand.
Congratulations. You just committing the crime of carrying a weapon illegally, and you did it without ever leaving your own property.