Most teachers are academics - students at heart, while most time-magagement texts are written for business people It is therefore important to understand the key difference between students and business people. Students strive to take information from paper and get it into their heads; businesspeople strive to get ideas from their heads and put it down on paper. For a student, having a lot of stuff rattling around in your head means that you are ready for your final exams, for a businessperson it means you are ready for a breakdown.
This simplistic point: that some people need to write down what they already know, is critical. You will have seen the different roles involved in teaching (here) and may have wondered how these different 'hats' can work together. The answer is simple: they write each other notes. This act of writing things down is important in time management and in stress management: as far as possible we want to clear information out of our head and onto paper as far as possible, until we actually want to process that information.
If you are following the magpieplanning method of lesson-planning you will have noticed that there is a constant emphasis on writing-things-down: seating plans, timetables, term-dates, etc. This is not because intelligent teachers are incapable of storing these details in their heads; it is because they shouldn't have to carry this stuff round in their heads - they have enough to think about already, thank you.