It would be nice if you could set a boundary once and have it be as good as law.
But it’s worth remembering that even laws need to be monitored, patrolled, and enforced.
The strength of the boundary doesn’t come from the tone of your voice the one time you set it… or in the size of the intentions you have behind it… or in the seriousness of your body language when you talk about it.
The strength of the boundary comes from the strength of the enforcement of said boundary.
For example, driving 5 miles per hour over the speed limit will rarely get you a speeding ticket—it’s rarely enforced. But, running a red light? You’ll almost always get ticketed for. The latter is enforced significantly more than the former.
Now think about how this applies to the boundaries you’re trying to establish and maintain in your life. Are you setting 5 miles per hour over the speed limit boundaries that are only enforced… never? Or are you setting running a red light boundaries that are enforced every time. Think about the boundaries you’re trying to establish with yourself… your loved ones… your co-workers… etc…
People (you included) don’t respond to the announcements… they respond to the level of the enforcement.