Well. It's a bronze age planet where an officer thought to be KIA years back has actually given the locals Starfleet tech and made himself king. Also, he is bitter because he was left behind by the Enterprise.
Also there are asteroids on the planet that give off radiation that affect a person's memory and make them forget nearly everything -- their name, their history. So the landing part of Pike, La'An, and M'Benga are up a creek.
And it's just as bad on the Enterprise. Everyone is forgetting.
Thankfully, there is a hero waiting in the wings. She flies the ship!