Why are so many people incapable of admitting that they made a mistake and handling it gracefully? Is this something we can add to the school curriculum as a skill or something?

The way our police system is structured is horrendously broken and encourages this kind of things in its officers, which can only be addressed with a complete overhaul of our approach to public safety, but even with that aside, can we please as a population put more emphasis on being able to handle making mistakes without doubling down?