You also use the central locking system when you're driving. It's not the first time that while you're stopped in line or at a traffic light, or for any other reason, someone opens your trunk or doors to steal what's inside and escape on a scooter.
You've done the shopping, they saw you putting stuff in the trunk, or you put your purse on the back seat or next to you, and they come up to you, open the door and steal what you put there.
So you always drive with the doors/trunk closed, and you do this with the central locking system.
Usually, in other makes of cars, anyone inside can pull the handle and open the door without any problems (obviously, the child safety lock isn't engaged). In the Honda, this only happens with the front doors; in the rear ones, you have to release the lock, otherwise the door won't open.