Kinda of a joke, kind of not.
I know it’s a marketing/branding thing, but still it seems odd that everything, no matter how simple or how complex, can be reduced to 24 hour-long lessons by good ol’ Sam.
How about 12 hours? 36 hours?
I don’t understand what the question is. Are you asking whether there are topics that don’t have a “Teach Yourself _____ in 24 Hours” book? Or are you asking whether those books are anything more than quick introductions that make diving into more encyclopedic references a bit easier?
The answer to the first question is yes: there are no such books on quantum electrodynamics or algebraic topology. And the answer to the second question is no: if you teach yourself Java in 24 hours, you may be able to write a few basic programs, but you still have a lot to learn.
Who’s Sam?
I’ve no idea what he thinks.
I don’t know who Sam is either. From the question, I take it is some kind of Dummies Guide to X. There is value in that if done well for some subjects but it varies by person and topic. You can’t learn a language in 24 one hour lessons by any means but you could learn the basics of using a sewing machine or even landing a small plane.
Stoid, this isn’t Da Vinci Code. Just tell us our mission here.
Actually, I found my answer. Sam’s Teach Yourself series includes teaching yourself things in 10 minutes, in a snap, and “an hour at a time” without any limit on it.
That’s all.
He moved into the “complex subjects made simple” book market after the failure of his first major merchandizing campaign, to popularize green eggs and ham. 
Good job.
But it took you more than two hours! Sam could have taught you how to get your answer in five minutes.
I think it’s a similar pattern with the majority of topics, because of the way the human mind works:
Generally, you can distill the key principles of any subject or skill into the 24 hour format, because if a subject is so complex that you couldn’t do that, we’d naturally break it down into multiple subjects. And not just for the book’s sake, I mean because we have trouble keeping lots of principles in mind at the same time – we’d break it down and specialize.
Mastering a subject however always takes thousands of hours because the bar for “master” is set by all those other jerks who’ve dedicated thousands of hours to the subject.
But what about quantum physics, say? IMO you could definitely get a good working knowledge of QM from a dummies-style guide (in fact, I’d be surprised if such books don’t already exist). Being able to tackle the maths though would be asking for too much from such an introduction.
History.
I rest my case. 
It depends on what you mean by a good working knowledge. Quantum mechanics is nothing but math, so you really can’t claim to have any understanding if you don’t have that math down. But there are pop-science books out there that detail the major theories and ideas at a level that most people can reach.
I was just saying that people often don’t do a like-for-like comparison; they say it’s not possible to do a QM dummies book because you’d still have lots to learn. But you can say that about most topics.
Having said that, QM is exceptional because even as you break the topic down you’re left with subjects that most people still find difficult.
But we come back to how the human mind works. Most mathematical areas are based around relatively few principles. You can distill out these principles into a short guide no problem.
The difficulty comes with what is required to make such maths come naturally, such that readers could apply it to complex problems. Most people, even those with a relative aptitude, cannot acquire such an intuition rapidly.