It sounds simple but most of us don't admit when we're wrong. We hope that nobody notices and just move on as if nothing happened. I wouldn't call it a character flaw but rather human nature.
Admit when you're wrong and add it to your working agreement? Why do it? Is there any good that can come out of it? Well, chances are the people you're surrounded with have already realized that you were wrong. Admitting to it just shows that you're open, honest, courageous, and respectful. Also, the sooner you do this, the sooner you can stop doing things the wrong way and start doing them the right way. Wait, isn't that Continuous Improvement, sound familiar?
What if we could create a culture where it's ok to admit when you're wrong? Is that even possible? Would people adopt it?
For many of us one of the first things we do with our Agile teams is create a working agreement. This typically includes items like; show up to meetings on time, make sure everyone is heard, etc. What if we added, admit when you're wrong?
I've tried this with a few teams and it has worked really well. However, the initiator has to get ball rolling. Once he or she admits to something you'll be impressed how quickly others follow.
The reason I think this works well is because it creates an environment where perfection is not the goal and nor is it expected, so it ends up reinforcing the art of simplicity.