If schools were designed around the premise “use it, or lose it”, 70% of the curriculum could be scrapped.
Discussion
No, 'cause no one ever uses the exact same 30%.
Unless you are just job training, what you learn isn’t as important as engaging in learning. The content is like the scaffolding used to build intelligence. It is removed at the end of the job and the intelligence remains. Content specificity probably does not matter until graduate school.