Every single person I know well has a double standard for something. Such as “I don’t need to improve my driving but everyone else sure does” or a “do as I say not as I do” rule, etc. Though certainly some more than other. This leads me to believe all people do it in some way.
Is it simply human nature?
The highest standard is the standard we hold others to. I try holding myself to the same standard, and continually fall short. Teaches a hell of a lot of empathy and humility though