Thanks for reminding me about Lockhart's Lament, I had almost forgotten, but I agree with everything in it. Maybe a solution to Lockhart's problem would be to

Thanks for reminding me about Lockhart's Lament, I had almost forgotten, but I agree with everything in it. Maybe a solution to Lockhart's problem would be to actually do that, take the current state of the art of mathematics, what the doctors and professors are working on, do a topsort on all the prerequisites and make that the whole mathematics syllabus from beginning to end. As Salviati explains to Simplicio, the traditional educational milestones are irrelevant because most people forget them anyway and just use calculators. Someone coming out of school only knowing set theory will be no worse off than someone coming out of school knowing long division, because neither of them will actually do any long division, they will both use a calculator.