The following is in light of a question posed on Quora asking ‘Why, even at an age of 20, am I still very childish? Is it a mental disease?’
Allow me to give you a perhaps more controversial answer. If you are childish at twenty, thirty, forty, fifty etc., it is because (a) you can be; (b) you are used to being so; (c) the powers that be want you to be; and/or (d) you may have a legitimate disorder playing a significant role.
(a) I say “you can be” because if you lived in the early 1900’s and prior, if you were childish at an adult age, you would more likely have been (1) a pampered aristocrat who could afford to be and was indulged by custom and culture to be; (2) a beggar who, having little to no credibility, became such because you could find no stable employment due to your poor reputation; (3) a worker in some of the lowliest and lowest-paying jobs of the time, (4) a criminal by inclination or “necessity,” or (5) a criminal/patient in a prison/mental institution. Of course there were many cases that fell outside of these five likelihoods; however, the point is that the harsher realities of life (with the more class-based social order and the strict enforcement of it) often “beat” the childishness out of you, and if it didn’t, you suffered for your immaturity with life or livelihood to a much greater degree that now. In our day and in our land, an over-abundance of food, and far more easily obtained (relative) wealth and comfort, allows us to slack off more, delay more, mouth-off more, play more, sleep more, and so on.
(b) I say “you are used to being so” because it is true for many. It takes effort, purpose, focus, and discipline to mature. If it doesn’t come naturally to you (as it does for some personality types, where structure, gravity, and discipline are more intrinsic to the nature) then you will have to learn the harder lessons — often through much difficulty, setback, disappointment, loss, and other such negative experiences) — until that childishness is fairly diminished, or unless one becomes more, incurably hardened in it. If you are prone to childishness, and want to change, then you must be more intent on maturing, and even then, it isn’t a light thing, and you will likely have many slips and many setbacks. It’s a matter of remembering your purpose, calling it to mind, asking others to help you, studying up on the matter (self-improvement books, etc.), and (for those who know and love God) prayer, biblical reflection, and scripture-reading.
(c) I say “the powers that be want you to be” because starting around the latter part of the mid-1800’s, into the late part of the early 1900’s, the corporate, academic, and related powerhouses spoke freely, and wrote openly, about the need for the ‘retardation of maturation,’ as it relates to the American and British populace. The well-respected and renown former NYC teacher, John Taylor Gatto, in his thorough and extensive work “The Underground History of American Education,” provides much detail (with citations) of how corporate and academic leaders worked together to make the average citizen less entrepreneurial in orientation, less independent and self-sufficient in nature, less critical in their reasoning, less discerning in their choices, and less sober in their thinking. They wanted pliable workers, best suited for factories; security positions like the police and military; office and retail workers; etc.. Though there is nothing wrong with these positions, some of the listed work wasn’t natural to many Americans before the industrial age and especially before the power and mass use of oil/petroleum (for transportation, production, etc.) became popular. I have personally visited libraries, and reviewed the old books, wherein the industry/academic powers made it clear that they work working to advance this retardation of (or delay in) maturity. They did it through extended mandatory schooling;the mass proliferation of sports teams and stadiums; and later through radio and television “programming,” modern music, etc. The end result can be seen today.
During the war of 1812, and at the age of twelve, Admiral Farragut (who was not yet then an Admiral) was given command to bring a ship that he and his shipmates captured into one of our ports. By twenty-two he was the lieutenant of a U.S. Naval vessel fighting pirates in the West Indies. By twenty-four, he commanded his own U.S. Naval vessel also fighting the pirates. There are numerous sources, numerous sources of people before World War II accomplishing amazing things before the age of twenty, and often even younger (from ten to fourteen). There was no (or very little) “adolescence” back then as DeToqueville noted. You went from a child to an adult with little middle/extended period. As a result, these youth were more adult in nature than many thirty and forty-somethings today. Again, this is by design, the powers that be love to have it so, they love to have us buying things we don’t need (consumerism), accumulating things we don’t need (materialism), focusing on games, and sports, and “gadgets” (a synonym quite often, for “toys”). They want us focused on lust, gossip, (entertainment) stars, the next big threat, movies and television, music with little positive but much negative influence and meaning (and it is hard to escape this even when knowing about it)…
If you doubt the reality put forth, visit sites dedicated to preserving old commercials. Compare the nature, tone, and sobriety of the commercials from the 1940’s to the late 1970’s to what we see today. In our day, adults are portrayed as being stupid, lazy, gullible, uncouth, hedonistic, petty, and otherwise… ill-behaved/mannered. Listen to the messages in the music lyrics today, listen to the almost nursery-rhyme patterns of many of the vocals, and compare them to the era before the mid 1960’s. Moreover, compare even the music of the 1960’s through early nineties, to what we have today (we have abject nonsense in comparison). Also, as another test, compare the rich prose, the complex social/moral/psychological constructs, the vast diversity of vocabulary and terminology, and the complexity of plot found in classical literature (e.g. before the 1960’s especially) to the popular novels of today. Few in our day could handle reading the classics, except in abridged form … few in our day even read books, period.
(d) I say “you may have a disorder.” There are mental issues/disabilities/disorders that affect inner and manifest maturity. For instance, I personally have Non-Verbal Learning Disorder (NVD or NVLD), which is still recognised in Europe as a separate diagnosis at last check, but know is grouped as part of the Autism spectrum in the U.S. Those of us with NVLD tend to have very high vIQs (the verbal reasoning part of the IQ), with significantly lower-in-comparison pIQs (the physical/spatial portion of the IQ). Like many of those on the spectrum, our maturity levels (in view of our actual age) do not match up with many of our counterparts in the neuro-typical population. So though we may have significantly higher IQs, a greater breadth/depth of knowledge, etc., we (in comparison and contrast) do not have that expected degree of wisdom that should accompany such knowledge, ability, years of living, etc. We may look younger into older periods of age, sound younger, SPEAK/ACT younger, accomplish less outwardly/manifestly at first, etc. but there is still much hope for us (statistically speaking at least; for we still have opportunities in this day, and in this western society, that others like us in times past did not have — as mentioned above). We often have to work harder to be more grounded, more mature, less compulsive, etc. — but it can be done, we just have to expend the extra energy (and obviously, as we age, we do grow — just like those in the neuro-typical realm… or many of them at least). There are simply neurological trade-offs to be dealt with, one gift or ability may come at the expense of another and vise versa. We must work with the lot/hand given us and make the best of it, improving upon our capabilities as we are able.
FINALLY, in closing, all of the above can play a major role in why we may remain immature/childish at twenty years or age and onward. Yes, embrace your inner child (as others say); nurture creativity and curiosity as much as possible; approach new subjects with child-like wonder; be open, caring, and honest like many children are; but remember (as John Taylor Gatto so aptly explains) there is a difference between being child-like (with the associated positive traits) and being childish, with the very clear negatives.