I've never been happier.
Sure, there are more responsibilities. But there are also much greater freedoms.
When I was a kid I thought that when I grew up I'd be able to get myself all kinds of toys and games my parents wouldn't get me. My mother explained that when I was older, I wouldn't be interested in those things anymore. Mostly, she was wrong about that. I still like the same things today that I did when I was barely in my teens like D&D, miniatures and fantasy toys. I'm a responsible adult but in some ways I retain child-like qualities. The benefits of adulthood with the best of childhood.
Also, as you might expect, I'm taken much more seriously as an adult. Despite my liking for fantasy toys etc, I was always mentally very mature but kids generally aren't taken seriously. Nowadays, my exterior and interior match: I'm treated now as I should have been a long time ago.