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?
Likely. Some people do it massively while others minorly. Im sure there are a few things im a hypocrite on but I can’t recall them atm. The old do as I say not as I do thing.