I can't remember if someone asked about this or not but I believe 404 refers to either:
1. the number of errors you created while trying to access the site in question.
2. the number of attempts you will need to make to actually access the site in question.
3. the number of people now required to fix the error you created while trying to access the site in question.
4. an arbitrary number someone pulled out of the air to make the error you created while trying to access the site in question look legitimate.
or -
5. the name of the information highway you ended up on by taking the wrong exit while trying to access the site in question.