When your site finally works perfectly between you, the browser, and your hosting provider... but then Cloudflare throws a 5xx error and ruins everything! The classic three-way handshake of web development where two parties are happily consenting to serve content, but Cloudflare's like "nope, not today!" Fun fact: Cloudflare handles approximately 10% of all internet traffic, so when they say "I DON'T!" to your requests, a significant chunk of the internet feels that pain. It's basically the digital equivalent of planning a perfect date and having the restaurant bouncer refuse to let you in.