Not to mention you can't remember strong passwords so you tend to write them down. I once had to generate a password for some military app that was so bad, it had to be some 20+ characters without any common words, nor could you use common numbers and symbols inplace of letters, so a password like, "P@$$W0rd" wouldn't work. I ended up writing it down somewhere... in my own special code I made up so as to confuse anyone who saw it (mostly inspectors who will write you up if they find passwords written on papers glued to monitors).