[ljk]

That's the thing with these "tutorials". I remember watching one video that was "Calculus in 5 mins". It made a lot of sense, but that was after learning it, but to someone who's never been taught the topic, these might not make any sense

[Tycho]

It's not a binary difference between learned and untaught. Many people have taken calculus classes and probably not enjoyed any lasting insight, either because the teaching was bad, or there were too many other subjects swimming around their mind at time. Or never taken a class but developed a surface familiarity with the main ideas. These types of tutorial could be useful for them.