At one time there were libraries. I remember learning calculus in high school as a sophomore by reading a calculus book from the library. Only could get it two weeks at a time and hoped that no one else asked for it because I had only been able to get through 20 pages a day.
But Khan Academy is a great idea. Not that all that he does is "easy" but most is exceptional. I also remember taking Continental Classroom in High School, on at 6 AM every day, and I think I missed the definition of a mole. Well, if you missed that you got lost and there was no recording the video, it was black and white on a 12" screen, and you always were trying to catch up with that damn mole, later in medicine I found out what they thought it was but it kept running around again and again. Now for Khan, great talk: