If you want to appear older online you should write properly. Proper capitalisation and sentences make your text easier to read. As it is they look like an uninterrupted stream of consciousness.

This might also help you offline. Try to structure your thoughts before giving them to the world. This takes time but should go a long way on making you seem like you got your shit together.

Your use of punctuation reminds people of when they've seen posts by 11-14 year olds. Do you not notice that adults in general don't do that?

I expect if you're unaware of something like that so immediately apparent to everyone in this thread that you may have other quirks and behaviours that strike people as childish.

If you sincerely want to change that you're going to need to ask the frank opinion of someone who knows you in person..

Probably because you're a child.

Sorry but I work with college students, if you're not 25+ you're another one of those children to me. Your writing style is very similar to theirs; it's very stream-of-consciousness with overuse of punctuation to try and accentuate your "points."

Grow up, get your spirit destroyed by the world, realize you can keep living without it, and I'm sure other adults will start to treat you like one.

ok, being honest here.

i remember you from a while back (old posts) and being straight up, you do seem kinda young and childlike. I do not know how old you really are, but if i was guessing, 14-16.

If you talk at all like you've written, I would treat you like a child too.

Maturity has nothing to do with your calendar age.

You are one of the very few users here on Lemmy I recognize, and it is not because you've been posting very intelligent things. In fact you posted this exact question once already (but seem to have deleted it by now).

I remember being 21 and I was more mature at 21 than you appear to be based on your post and comment history here, in fact I think I was more mature than you are now at around 14.

I don't know your situation, but I've noticed that people tend to do this to people who act immaturely. Your writing style, especially the use of 3 exclamation marks per sentence seems quite childish. If you talk in a similar way, that might have something to do with it.

i wonder

Do the RAADS-R test. In case it's more than 120 (I think that's the number, but it has a description), you may want to read what autism is and whether you may have seen some of the traits in you, and then may visit a psychiatrist.

I say that because autistic people often imitate some style of speech in circumstances not quite fitting.

Did the answers you got the last time(s?) you posted this question not tell you what you wanted to hear?

Think of the people who seem to do this to you. Pick the one who trust the most. Now ask them.

There are various reasons people may treat you as if you're younger. I would bet the primary reason is no matter how much you think you've grown up, those changes have to be seen outwardly for a while before people that knew you as a kid will accept it. It took until 24 or 25 before I felt people had stopped treating me with kid hands. Keep in mind as well that as people get older, younger people start blending together a bit and a 20 year old does not seem as mature from a 30-40's perspective. It's similar to how younger people often have a hard time telling apart old people's ages and they all seem "old". The final point I'd make is that swearing isn't something all adults do and is not related to maturity. It can be a sign of familiarity between certain people though. Swearing around family members is either something that comes with time or never, really depends on your parents/relatives.

Trying to push these issues in an "I'm a big boy now!" manner will generally backfire and get you treated young for longer, because it's a very childish thing to do. I am not all-knowing so I don't like giving absolute advice, but personally I think the best thing you can do is not worry so much about it and continue acting in a responsible manner. If you show yourself to be mature, others will realise and treat you as such. If they don't then either you're not as mature as you think or you should find someone who you can have a more level conversation with. It's not so bad being young, anyway, "the grass is always greener" and you will miss it when people always look at you like an adult!

ikr, like fr, sometimes i think it's because maybe i'm just, like, short, but wtf no joke, one of my closest friends rn is shorter than me and with my other friends, i still get treated like i was less mature?? one time one of my coworkers actually said that, not cool wth, and i feel a bit outcast when they all act like that, like, this is just how I talk, so why can't they respect that i'm pretty much the same generation as you guys, i slouch just like they do, and sometimes they have even worse posture, but then like why do they have to low key drop these bad vibes on me, cause ong, it's so demeaning when they say something slow like they think they're being thoughtful, and maybe sometimes the nice people really are, but mostly they come across sarcastic and fake!!! but i can deal with, most of the time, idk

Back into the spirit of c/NoStupidQuestions -- follow up question! What do you think they believe Proper Adults act and speak like?

From what I can tell by your posts, you are treated like a child because you talk and act like a child. Have you tried, like, growing the fuck up?

My oldest daughter is 21, but she's still "one of the kids".

I know she's an adult now and will be finishing college next year, and out loving her own life very soon, but she's still my child. Even though you can go do anything an adult can do, you are still the same "child" that you're family has known since you were born. It's going to take time for them to get used to that.

Legally, turning 18 instantly makes you an adult, but it's going to take a lot longer than that for other people to realize it.

Also, early twenty something's ARE still kids. Very few people that age have actually "grown up".

You probably don't mention taxes and stocks enough.

Also, phrases like "back in the day" and "in my youth days" help.

When you are with people in person, try to sit straight and when standing/walking try to look like a superhero all times.

You should look into checking if you are autistic. We get infantilized a lot

If you just mean your relatives, it's important to know that what constitutes 'young' changes as you age. As someone in their 30s now, early 20s and below feels young to me personally. If your relatives are much older than you, especially if they saw you growing up, it's likely you'll seem young to them forever. That isn't to say you should be infantilized your whole life, but just that it stems from differences in perception. If you feel like you're being treated lesser than other adults, try to tactfully explain how you feel. Maybe you're feeling excluded and that hurts, or perhaps being called certain things is belittling to you. Ultimately though, the most important thing is that tact, because it's very likely not malicious, your relatives likely aren't trying to make you feel small or invalidated.

As for anyone else in the street, or perhaps online, there's usually something that makes people naturally assume youth. I don't know what you look like obviously, but online you typically have very little information to work with. Usually just the words that are spoken, and maybe an avatar to go along with it. A number of people have pointed out your typing style already. I won't belabor the point, but I will say first impressions are extremely quick to make, and quite influential. I personally try to talk to anyone with tact and just 'as a person', but it's something I feel doesn't come naturally. I really only ended up doing it because I spent a long time in moderation type roles, having to mediate issues with people and events.

Tl;Dr: It sucks, but people probably aren't doing it to hurt you. Talk patiently to them, also type more formally.