Though common to most of us, it is further defined as:
The requested resource could not be found but may be available again in the future. Subsequent requests by the client are permissible.
To me, 404 represents a dead end but certainly nothing final. A denial, if you will, but an acknowledgement that it's okay to hope and, at some point, try again in the future.
Please join me in celebrating this error code today- April 4 (4/04).