Indeed. The site is amazing, and Kalid is to be praised to heavens and back.<p>But a man is a man, and he can do so much. My main, very sad, take away from that site, was how ridiculously bad math teaching is everywhere else. It&#x27;s easily in the criminal area.<p>To put but the simplest of examples, I have an MSc in math, and I was never told in uni (or figured out by myself), that &quot;i&quot; is &quot;turn 90 degrees&quot;.<p>That site should be required reading in many unis, to teach people how to teach. At least save the new generations :-&#x2F;