I haven't watched the video, but here's my experience on learning the fretboard. (FWIW, I wouldn't say I'm 100% confident, but I can find the pretty much any note I want within a few seconds, at this point. I know some better than others.)
I learned the notes on string 6 and 5 (which automatically gave me string 1), first.
Then I learned the octave positions based on what I already knew.
Then I learned common interval patterns (e.g., 5th, 7th, 6th, 9th, etc) from the root.
From there, you can get to pretty much any note you want if you think about it. After a while, you start to just kind of "know" where the note is and don't have to think about it any more.
I say the most helpful exercises, for me, were the circle of fifths exercise (play every C, play every G, etc), and also learning triads on different string groupings (e.g., triads on strings 1-2-3, 2-3-4, 3-4-5, 4-5-6).
In my case, it definitely wasn't something I learned "all at once." It came a piece at a time, over a period of time.
EDIT: Sight reading exercises helped, too.