Star Wars Rogue One: 20 WTF Moments

This had been heavily speculated before Rogue One's release, but it was still somewhat unexpected to see fans actually get their dose of wish fulfillment.

It's revealed that Jyn's father Galen, who is responsible for the Death Star becoming operational due to his research into kyber crystals, intentionally built the exposed exhaust port into the weapon's design as a flaw, in the hope that the rebels would be able to exploit this, as of course they eventually do in A New Hope.

To hear the most ludicrous "plot hole" in the franchise somewhat rectified after four decades was extremely cathartic for many fans, and while it's still pretty absurd that nobody else questioned Galen's design choice, it at least makes more sense now.