The eternal lie we tell ourselves: "It works on my machine!"
Left side: Your code running on localhost - a magnificent beast with muscles that could bench press a server rack. Status 200, everything's perfect, and you're basically a coding god.
Right side: The same exact code after deployment - a pathetic, malnourished doggo surrounded by CORS errors, cookie sharing issues, and bad requests. Suddenly your beautiful creation is about as functional as a chocolate teapot.
The production environment: where developer confidence goes to die and debugging nightmares begin. But hey, at least it worked in development!