That's ADHD for you.
A former coworker of mine lamented this - "I start so many projects or hobbies, but just when I feel like I've learned a lot I lose interest". I had to point out to him that his hobby isn't - whatever, sheep shearing or book bindery or underwater basket weaving - but rather his hobby is learning things. That's a common thing for ADHD people, absorbing all you can in a rapid amount of time, devoting every minute of thought to something, and then suddenly completely forgetting it exists until you get the domain renewal notice.
At least you (seem to) have (some degree of) acceptance of the circumstance and recognize the benefits of this behavior rather than just focusing on the drawbacks; too many people have this behavior and think it's a personal failing, when really they just have a different hobby than they think they have.
This "hollowness" is something I intimately understand as someone who used to play hundreds of hours of single-player RPG games. You can make-believe that this world is real, and it works for awhile, but you eventually exhaust this willpower and the lack of real depth eventually crashes into your world. Then I turn off the games and go walk around the mall, just to see humans doing human things again. I feel remarkably better after that.
Maybe we need AI as matchmaker and Master of Ceremonies, introducing people to each other and hyping them up to actually engage with one another.