What do you feel when you get a 4o4 error message when searching a website? Disappointment, frustration or inspiration? Or is it a missed opportunity to build a relationship by the website?
BTW a 404 code is part of a set of 4XX Error codes which are issued by servers when things go wrong.
In this TED presentation by Renny Gleeson, where he claims
[A 404 page] is the feeling of a broken relationship he makes us think about what a missed opportunity our website 404 page is. And illustrates his talk with some inspirational 404 pages.