Lot to unpack and there is some real gold here (at least for me).
> In this world, there is no one you can change. Not your spouses, not your friends, not your kids, and of course not strangers on the internet. Only yourself.
A few years ago, working at $PREVIOUS_COMPANY, we had 4-5 hours of company-sponsored time with a a coach/counselor and she also said those words to me. It's something that hit something inside myself and it's really, really true and... liberating, when you fully embrace it. Especially when you are a parent, but also in many other situations. You cannot change the others. You can only change yourself.By changing yourself MAYBE you might influence others - especially kids, by being a virtuous example, and they can decide to follow what you do. But changing people, let alone by arguing, that's impossible and will only cause you frustration.
"We but mirror the world. All the tendencies present in the outer world are to be found in the world of our body. If we could change ourselves, the tendencies in the world would also change. As a man changes his own nature, so does the attitude of the world change towards him. This is the divine mystery supreme. A wonderful thing it is and the source of our happiness. We need not wait to see what others do.” -- Mahatma Gandhi
Also, attributed to him - "Be the change you wish to see in the world"