The most common scenario for this to happen is when you simply forget your password. The real problem, however, is when (for whatever reason) your user account does no longer exist or it appears like this is the case. There are different steps you can take to solve this.
Did you know? Most WordPress releases have code names
One of the main reasons why we like WordPress so much is because there are so many plugins out there that can be used to make our websites better and easier to administrate. In this little article I will show you how to create a "Recent Posts" plugin, so you could get the general idea. It will be best understood if you are familiar to PHP programming language.