What letters are not used in Vietnamese?

Okay, here's my attempt at editing your piece, trying to make it sound more like a natural conversation:

"So, get this – you know how we all learn the alphabet, A to Z, right? Well, I was totally floored to find out that Vietnamese doesn't use the letters F, J, W, and Z! Seriously! It's like, what's up with that? Those poor letters!

I mean, F, J, W, and Z... they're in everything, aren't they? Or, well, a lot of words anyway! I remember struggling with 'jazz' when I was learning to spell – how could you not use a 'J' or a 'Z'?! It just feels... incomplete without them, doesn't it?

I guess it just goes to show how different languages can be, and how Vietnamese has managed to build such a rich vocabulary without needing those particular characters. Still, makes you wonder, doesn't it? What's the story behind that? Was there some historical reason they just... vanished from the Vietnamese language's family picnic? I'd be so curious to know! It's just one of those little language quirks that makes you go, "Huh!""