Actually this is interesting, I did this myself growing up. But I seem to remember that it arose because of slowly changing password requirements. Like I remember having a password in my teens for Myspace and other web services, and one day when signing up for a new service I was prompted with "your password must contain at least one number". So I just took the same old password and put a number on the end of it. Then a few years later the same thing happened with special characters: "Your password must contain at least one number and a special character". So then "okay, just tack a special character on to the password I already know" and voila <word><number><special char> is now my password.