The career advice you didn’t get taught at school. It has -at the time of writing- been 13 years since I was at school, and it is only later in life you acknowledge how small a part of life school plays, but at the time it quite literally is your whole world.
While the national curriculum might still be questionable as to how much of it you’ll actually need in the real world, your teachers spend a lot of time trying to prepare you for the world of work and plug in career advice where they can. However, what you are told and what you experience in the workplace and further education can be quite different.