Education today assumes that (1) every piece of information can be categorised into exactly one field of study (subject). Then, (2) these subjects can be taught independently from each other. Furthermore, (3) lessons of different subjects are fungible, i.e. freely interchangeable.
The first assumption is simply false. Several topics are interdisciplinary, spanning two or more very different categories. For instance, brain-machine interfaces are both part of neurology, thus biology, and electronics, thus physics.
However, the falsehood of this assumption is not very important. Much more significant is the fact, that today schools have to teach several skills: foreign languages, digital literacy, and so on. And unlike collections of facts, skills cannot be learned by rote; they have to be practised on some problems.
Here, assumption 2 enters the picture. Since pieces of information have been sorted into separate subjects, the skills that need to be taught, are given their own subjects. Foreign language classes, and information technology classes. In these classes, the problems for students to practise on have to be created artificially.
Even if they do not understand exactly what the problem is, students do feel that these problems are made up. That there is no real reason to solve these problems. That they are entirely pointless. Consequently, the students' motivation will be sapped, to say the least.
The solution is to forgo the flawed idea of teaching skills in separate subjects. Instead, mix each skill-centered subject with one or more fact-based ones. The latter would provide real problems, real topics, on which to pracise the skills in question. For instance, geography classes could be held in a foreign language, while history could make students use modern IT.
This would also mean each lesson does double duty, both transferring knowledge and honing skills. As a result, the timetable could shrink—or include new fields of either kind. For one, I would include economics in the factual curriculum. And in the category of necessary skills, working in groups is an obvious must.
Indeed it is so evidently a requisite of life, there is already a push for its inclusion. Which is a tough case, since the current system is built on assumptions of isolation. This is at its most visible in exams: students are expected to work on their own, without any external sources of information (written or otherwise), in a very short timeframe on the order of an hour.
It would be hilarious if it were not so tragic. Life is not about knowing facts, and never was. It has always been about accessing information. These two just so happened to coincide until quite recently. But with digital technology being so ubiquitous, now more information is accessible than ever before, and memorisation is increasingly less competitive.