I have heard many times that once a habit in life is established it takes 3 weeks for a person to mentally process the change and leave the old habitual behaviour behind.
I never thought much about that possibility until recently when I changed my computer passwords. It has taken, including today, exactly 21 days for me to put in the new passwords automatically, without having to stop and think first and without dazedly and mindlessly typing in the old ones when I first stumble into my office in the mornings.
It is incredibly embarrassing for some reason to accidentally type in old passwords and have your computer remind you with an onscreen message that you have changed your passwords X number of days ago....didn't you?????? The computer makes you feel that it is far more intelligent than you are, stupid password changer who can't even remember that you did!!
So now I am officially a stereotype. It didn't only take me approximately 3 weeks to get in a new habit with my computer, it took me exactly 3 weeks.
Next time I have to change some long established habit, particularly as relates to my computer, I am going to pay better attention and try to leave the stereotypical behaviour behind! It is my personal goal to give my computer fewer reasons to mock me with messages on my own monitor!