emily: what is the myth of sal khan and what is the reality? sal: the daily life.'m still changing diapers and cleaning burp up off the floor. [laughter] the other myth is --sometimes it looks like these things just happen overnight. i don't think i'm speaking just for myself. i think i would be speaking for a lot of folks at silicon valley who've started things. you hear about their success, but they have a string of failures that get swept under the rug. i probably got dinged by 40 foundations when i was trying to get khan academy funded. it is never, kind of, as clean as it looks in the outside. emily: do you think videos can replace learning in a classroom? ♪ emily: you still create most of the videos, don't you? sal: i still create a large number of videos. it's one of the things that keeps me happy. emily: so how many videos have you made, personally? sal: i think around 4000 videos. most of what we have been investing in is an extension of some of that software that i started with my cousins in 2005. where it's students can go, and learn at their own pace, i