All the time. Literally. I am narcoleptic, so I’m constantly in and out of sleep. YouTube works well for me because I can’t usually make it through a TV show or movie. A 10-12 minute video is possible for me to watch sometimes, but I still have to replay a video several times, then mentally piece it all together quite often.
I checked my browser history, and in the last 3 days, I have watched 57, 63 and 82 videos. I do not have the stamina to figure out a weekly average.
There are times that I am in and out of consciousness so quickly, that I can’t move to search for a video or even select a recommendation, so auto play will just play what is next on the list. It will stop after a few videos and wait for confirmation I am still watching. I am awake enough to listen to the video, and hit the button to allow it continue when I hear it stop playing. I actually retain a surprising amount of what I heard during these periods. I’m being force fed (only sometimes useful) information 24/7.