Allegories about Arid Mathematics Teaching

How is current mathematics teaching like teaching music without instruments or teaching art without using blank canvas? Find out by reading Paul Lockhart's Lament.

I found this on Vlorbik on Math Ed, where one of my posts was featured recently. You can also get a sense of how well it resonates with the Kitchen Table Math crowd. It also explains many of the challenges, including teacher content knowledge, that are being explored there.