If you’ve more than a couple of years of experience in IT, you probably have stumbled upon the following quote: There are only two hard things in computer science: cache invalidation and naming things. — Phil Karlton Then, because it’s such a great quote, it evolved: There was a 'Moved Permanently' error fetching URL: 'https://twitter.com/codinghorror/status/506010907021828096' However, I think that the initial quote is misleading.