Yes, it has happened with me. I was acquainted with my old password. Then somebody advised me of changing the password frequently. One day I did that, Next day when I was trying to open my email account, I was unable to do so. It was telling me that, I am using incorrect password. I understood that, I have forgotten my password. Then I tried to curse myself, why at all I have changed my password? Who inspired me to do so? After a lot of struggle, when I could not retrieve my password, I used the forgotten wizard. There also, I have forgotten some basic answer. Actually it could have been, because of some spelling mistake.