I use a "save" feature on youtube a lot - I keep playlists on many topics and not only go back to re-watch videos that I found useful but also just try to have a list of "to watch" and put new videos there to avoid binge-watching things when I am procrastinating - I add them there and watch later - during the special "youtube time" (things we do to trick ourselves! :)
As I recently realized you cannot save videos that are marked that they were "made for kids". And I kept all my videos marked as "made for kids" - as I thought that watching as someone draws or flips through a sketchbook is an OK activity for kids :) But now I corrected this - and you can save the videos to your lists.
Here is the one I uploaded today to test: