Not really, but it's advisable.
We tend to associate maturity with responsibility - accountants, and paying bills; doing the groceries, and becoming the beige, boring grown-ups that we used to despise and pity in equal measure as children.
For a long time in youth, it's considered attractive to pass yourself off as mentally younger, crazy, loose, a bit of a wild card, all in hope people will continue to see you as fun. Oh, of course I'm not a mature, responsible, boring grown-up. I may be in my 30s or 40s but I'm still fun.
Of course, what we fail to observe is that that translates to retaining a childish, immature view of the world. Feels insufficient when you consider we could evolve, and how much more we could grow by embracing maturity, and the coming of new responsibilities that come as we get older.
Fighting the natural passage of time isn't chic, it's immature, and largely out of place. I mean, if you meet a 21-year-old girl who's a bit kooky, a bit irresponsible, airhead, etc., you may think it's charming. If you meet someone who's 45 and like that, you'll just think it's kinda weird.
Also, while it was natural to have this idea that adults are boring as kids, I don't really see that we must maintain it as we get older.
What's boring about grown-ups is that they forget to have fun, are serious all the time, laugh at silly voices, have tea instead of vodka, and try to get enough sleep. Well, there's nothing wrong about those last two, and really, the first two can easily be rewritten as
Must I become boring?
Except, why do we need to equate the two?

Why can't maturity mean...knowing how to meet a hard situation? Death? Heartbreak? Illness?
Do I have to? No, but it's certainly desirable, given that the world will throw them at you.
Or, why can't maturity mean figuring out how to foster openness and honesty in a relationship when you're hurt and your emotional triggers have been activated?
Again, must I? Well, unless I want to end up in a) a highly toxic relationship, or b) alone, fleeting from short-lived, surface-level affair to affair, then yes. You kinda should.
Or, on a more practical level, is maturity doing the dishes, calling the plumber, paying the bills, and so on?
Yes. Is that boring? Certainly. There's so much stuff, vastly more exciting, that you could be doing. But until we develop a solution to automate these boring, mundane tasks, you're doing them first as a trade-off to get out from under your parents' roof and earn new liberties for yourself, later, hopefully, to help your relationship run smoothly, then finally, perhaps you do them so that your children don't have to worry about cooking, or cleaning, or stuff like that, and they can instead play, or learn, or otherwise develop.
So do you have to? No, you can stay in your parents' basement, or find a partner to mooch off of for the rest of your life, but that does not come freely, and you may find it has far more expensive trade-offs then learning to be responsible for yourself.
Finally, do you have to become boring?
Not really, no, but none of the things actually force you to be boring. You can be mature and responsible, while at the same time nurturing a wonderfully playful and creative attitude to life, while holding a boundless curiosity towards the world.
Do practical gags, tell jokes, make voices, invent stories, run a ruse, run in the rain, remember to play and climb a tree. Keep light and hang loose. Meet your life with curiosity, and you're guaranteed not to become "boring".
Also, mind how you go. Looking back, it seems to me my definition of "fun" has changed dramatically from what it was when I was 20, and then again from what it was when I was 6. I consider myself quite a fun person, despite these changes.
I wrote this as a response to the Ladies of Hive question of the week,
When we hear the phrase: "Aging is an obligation, maturing is a choice," do you agree? Do you think aging is an obligation? Do you think maturing is optional?
Most things in life are ultimately optional. But in my opinion, there's nothing sadder than being 50, acting as though you were still 21. Obviously, keep the playfulness, keep the curiosity and openness to the world, but also adapt to the way life unfolds. After all, if you're going out every night clubbing, getting wasted, and hooking up with transitory one-night-stands, chances are the 20-something-year-olds in those clubs aren't gonna think you're "fun", they're gonna think there's something kinda off. Because despite our fear of growing up, part of us expects maturity to be inevitable.
Now, whether we also see it as something desirable that we welcome into our lives, that's a different question.
