Same. When I was 15, I wrote a little script that used youtube-dl and then ran the resulting download through mencoder to strip out the audio. I don't see why teens today can't do the same :-)
Oh dear, the Wifi I was using when I posted that was terrible and - a trip to Venice later - I am unable to delete the repeat comments. I'm very sorry :-S
Hm, it may not have had it a number of years ago, I'm unsure. I would have looked at the man page though so I'm certain there was a reason for using mencoder in the end.