Cinematic colour grading and adjusting hues you didn't notice. Adding visual effects no one asked for but everyone ends up loving. Colour grading and scrutinizing every frame until we've seen it so many times we're starting to feel a bit nauseous.
But that's the price of perfection. Let's face it, this level of nitpicking in cinema isn't for everyone. Good thing we're just the right amount of crazy to find a kick out of it. After all, if we didn't have fun doing this, who would?