I genuinely don't understand how this works for so many people.
When i watch something, I watch it and wont sleep until i make the concious decision to stop paying attention and close my eyes. Same with books or anything really. Maybe music works
Depends on the subject and how much interested you put in it. If the video is just random dumb shit with music, then you fall asleep. If it is a nice interesting movie you may stay awake. Even so, if the movie is boring, you may fall asleep.
ehhhhh, its a heavy sleeper thing for me I think. I usually don't make the conscious decision of falling asleep, I just lay in bed until I just pass out. My brain just gives up and disconnects. I'm a heavy sleeper, and I need like 30 minutes minimum between opening my eyes in the morning and actually getting out of bed.
I'm also watching streaming services too and it happens a lot to me that I'm watching a series in bed, I fall sleep, and wake up to realize I watched many chapters of the series so I gotta watch them again later, this time for real.