As I've grown older, I noticed the cardinal pleasures don't hit like they used to. I also get nostalgic at times about the wonders of youth, experiencing things for the first time, falling in love, getting my heart broken, the little things of life.
I've gotten great pleasure and reassurance knowing that's all ahead of my children. No matter how I progress personally, time marches on and I get to see my kids discover the world. If I do nothing else in my life, I would still feel immensely fulfilled.
I think the recent rise in things like Disney adults and interests around video games or popular media (TV/movies) is a kind of biological response. People are free to do whatever they want of course, but I can't help but think that these people, at least biologically, are drawn to these more adolescent interests precisely because they're not experiencing it through the eyes of their children.