Speaking as a non-smart person of boringly average IQ, so perhaps I'm inflicted with the myopia of someone without the raw intellectual horsepower of a 2-3 standard deviation smart person. But I do have an insatiable curiosity about the universe: for context, having the capabilities of a Banks'ian Culture Mind would be really neat to me.

My theory is people get bored because they self-select what interests them. That is, out of all inputs pouring in through their senses, their mind too-aggressively prunes the torrent of data, and they're left with a paltry amount, and as a consequence correctly declare that curated trickle as "boring".

Take your example, "watching a single youtube video on repeat dozens of times in a row". On the first pass, the video repeats over and over, what is there to counter that it isn't boring if you remember all the details? But do you really remember all the details, or are you fooling yourself? See if you can predict tiny details of the presentation in the video, for instance. Say you have perfect photographic recall, and you really can recall with perfect precision and clarity every moment of the video. Wouldn't that be sufficient cause to claim it is boring to watch it over and over?

Peel back a layer, and wonder about say, what would have motivated someone in the video to pursue whatever it is that they are displaying in the video. What kind of training would it take to say, balance a spoon on your nose? What kind of time commitment?

Peel back a different layer, and wonder about what specific details the young child is capturing with each pass. Talk with them about if they noticed some detail in the video after a certain viewing pass. Ask them what they like about it, in specifics.

Peel back yet another layer, and wonder about the implication upon cognitive neuroscience research. Are there pleasure hormones that reinforce repetitive learning better than without those hormones? How does that impact our understanding of machine learning?

Once you start looking around you this way, the details you can uncover go recursive and fractal. Lots of old religions and mysticism have expounded upon this way of perceiving the universe. If it helps to visualize in more modern concepts, then I sometimes liken this approach to "playing computer", except pretend the computer is the one that runs the simulation of our reality, and imagining all the details and principles that would get expressed in the simulation "software", right down to the quantum level. There is literally not enough time in the universe for a human mind running on chemical connections to run out of entertaining lines of thought this way.

Do you have any suggestions for boring bureaucratic meetings with lots of contrived jargon? That's where I struggle to find entertainment.