In two days i was able to listen through half of cs231n in my spare time by listening on the youtube videos with higher than normal speed.
Nowadays i always listen to youtube videos with 2x or 3x speed.
With normal settings you can st the speed up to 2x. If you want to get the video faster than that you need to add a plugin or bookmarklet to achieve that.
You can drag these liks to your bookmarks bar, and get them as speed buttons to adjust the speed of your youtube videos…
Also, check out this video on how to learn advanced concepts fast: