My take is that you really haven't found this love in your life yet. You are trying to pigeonhole other peoples passions (like youtube vids and OS projects) into yours. That will never work long term.
For me, it was music; I loved it so much that you couldn't stop me from playing, and pretty much all available time outside work was spend practicing and playing in my band at the time.
It was the ideal social lubricant as well, as being a gifted "nerd" 35 years ago was a totally different thing then it is now. Literally, at work and school I interacted with the math kids that were often picked on and made fun of.
Playing and practicing live music not only soothed my soul, but gave me self-esteem and a ton of social status. And it hardly ever seemed like "real" work
I think that is the key for a sustainable hobby commitment.
[edits]