I guess I'm the outlier because I'm enjoying this journey of mine. I liked my 20's. I really liked my 30's. And, despite a major life change, I'm loving my 40's (I turned 41 back in June). Will I enjoy my 50's even more? Who knows, but I'm excited to find out. A lot of people say I look younger than my age, which I guess helps some.
A lot of it has to do with me still being mostly the same person since the beginning in terms of interests and hobbies. My parents regularly remind me: "You never change!" And in some ways, it's true. I'm still gaming, still writing reviews for fun, still staying active, still being a silly goose. All while being a responsible adult that goes to work, pays bills (I just got my car note in the mail for paying my last car payment), cooks, cleans the house, etc.
Another part of it has to do with having things to look forward to: Trips. Events. New game releases. Having something marked on the calendar weeks/months ahead makes the mundane less mundane because it's like you're always working towards something. For example, most Tuesdays I go to trivia with some friends. It's something routine and enjoyable and a fun thing to look forward to during the work week. I'm also in a book club and movie club. I've been kicking around the idea of looking for a doggie club since I'll be getting a puppy soon. I've got three new games to look forward to playing, too. And of course, there's this site's Secret Santa coming up which also excites me.
Sadly, part of getting older is seeing how bad things are politically (especially in the USA - yikes), environmentally, monetarily, etc. I don't have a remedy for that other than acknowledging that it's part of life.
So, personally, I deal with getting older by enjoying it. Yeah, there are times when I'm reminded of my age. I played kickball back in April and stumbled while running to first base AFTER MY VERY FIRST KICK. I got scraped up bad. But, there are times I'm reminded I'm doing things better than I did back in the day. I participated in the Spartan Race earlier in October and out shined some of the plucky, social media hungry 20-somethings. 
I was always told that getting older is a privilege, and I believe it.