What is the hardest part of MC'ing Apocalypse World

I recently ended a campaign for my players about a month ago and let me tell you: that was one of the hardest things to do as MC was bring all of their actions to a big huge epic climax and let it all play out. However, in lurking the forums since then, I've noticed people having difficulties with various issues. So, I figured it would be a good idea to share our experiences as MC's about what was the most difficult thing for us running Apocalypse World, be it simple general GM'ing issues, or something more specific to Apocalypse World itself. And we can learn from each other, and help other little baby MC's along the way. Think it's a good idea too boys and girls?

Wrapping up a game in general is difficult, especially one where the plot is so determined by the players.  It is a careful balance of plausibility, satisfying player goals, getting a good climax, and at the same time leaving a minimum of pressing loos ends.

For me however the hardest part is session 1, specifically the improvisation. I'm happy to improvise once I have the basics of the setting created but coming up with questions to set up conflicts and building a world on the fly is hard.  I come from the heavy prep school of GMing and while I don't really need that anymore I feel less confident without a well defined and internalized world.

The hardest part for me is making good PC-NPC-PC triangles. I think it's just difficult because of the group we play with, where we're used to all the PCs working together and sharing goals. I have to really work to find something that makes one PC want something that doesn't align with the goals of another PC.

This is my first time MCing, though, so I haven't seen how tricky MCing the last session is.

Getting everyone involved. I haven't gotten any complaints, but I usually end up walking away from a game thinking, "Ah, I didn't have enough people for the Gunlugger to shoot!" or "Why didn't I ask the Savvyhead what he was building? And if the Driver was helping?!" I try to pair people up and give everyone equal time, but I guess it's impossible to do it perfectly.

I'm with Yarrum! Keeping everyone involved. Sometimes it feels like all the threats and fronts I create don't seem to give the player characters stuff to do, because they don't seem to threaten things the player characters care about. It's a two way process though, the game is a lot easier when the player character have plenty of things and people they care about!

Without a doubt, the hardest part for me was the loss of a player or major character in the story. When we lost a player unexpectedly that had been at the core of everything we were doing, the entire game took a severe hit. This occurred three times over a few months, and each time it seemed toe drain the color of the world. Nevertheless, this was part of a learning experience, and the problems of NPC-triangles collapsing, major groups falling into obscurity, and dispersed characters are things that can be mitigated through game world design to some extent.

I personally have never had trouble with universally epic endings, but most of my games last 1-3 years, so I have a lot of time to think about them.

this is all gold, thank you to everyone who has replied so far