Maybe the Golden Rule works in make-believe land with all the rainbows and leprechauns and chocolate waterfalls, but here, on Earth, people do not follow that rule. So you might think you're considerate, but when was the last time you actually gave a shit about someone other than yourself, such as letting someone else have a parking spot, or waiting your turn, or letting someone else go ahead of you in the shopping market, or one of a million things that are just "randomly nice." How often do you give your seat up, or offer to help a stranger carry groceries, or open doors for people, or anything even remotely resembling being kind?
Yeah, maybe once in a while. But most of you are simply looking out for number one. Most of you are inconsiderate pricks that just pretend to give a shit about other people.
I treat people how I think they deserve to be treated, not how I want them to treat me. I'm not going to go out of my way to be courteous to some asshole, I'm going to give him the finger and call him a dickhead.