Are Buddhists supposed to feel superior compared to other people, and to brag about it?

The OP wrote:

If we're in a group with many other people, it's always them who bring up the topic of spirituality. Or if I meet an acquaintance who is not so close as to engage in deep conversations, and we would just generally exchange some pleasantries, "how are you? I'm fine, thanks", they instead start to instantly brag about how spiritually evolved and enlightened they are. No matter the topic, they sooner or later mention how enlightened they are. .....

What also happens almost every time, is that if we're talking about a non-religious topic, they still have a very strong opinion about everything, even if it's a technological topic in which I have experience and they don't.

I know some people like the above and most of them are, in fact, not Buddhists, but they could easily have been Buddhist.

I think this behavior is not specific to the Buddhist community. It's about ordinary (untrained, unenlightened) people, just being ordinary people, who are conceited and obsessed with their own views, ideas and opinions.

You can find many people on YouTube who have strong religious views (whether atheist or belonging to a religion) and have their own ideas on politics and economics etc. who passionately rant video after video, expressing their views and opinions.

From Snp 4.11, we see that clinging (also known as attachment), is the cause of such behavior.

"From where have there arisen
quarrels, disputes,
lamentation, sorrows, along with selfishness,
conceit & pride, along with divisiveness?
From where have they arisen?
Please tell me."

"From what is dear
there have arisen
quarrels, disputes,
lamentation, sorrows, along with selfishness,
conceit & pride, along with divisiveness.
Tied up with selfishness
are quarrels & disputes.
In the arising of disputes
is divisiveness."

Why? When you pick a stone you weigh it on your hand and say 'Ummm this is heavy". Then even if the stone speaks and says 'I'm not heavy' you won't believe it. In the same way, why do you call them Buddist?

Next time when you hear them speak a cryptic language say these people are probably grammarian or language translators don't say they are Buddhist.

But if you see them acting virtuously and controlled in speech you can say they have a trace of the Buddha. Then even if they say they are not Buddhist don't believe them.

It's not by name or by knowing complex syllogism one is a Buddhist but by action.

227. O Atula! Indeed, this is an ancient practice, not one only of today: they blame those who remain silent, they blame those who speak much, they blame those who speak in moderation. There is none in the world who is not blamed.

228. There never was, there never will be, nor is there now, a person who is wholly blamed or wholly praised.

229. But the man whom the wise praise, after observing him day after day, is one of >flawless character, wise, and endowed with knowledge and virtue.

230. Who can blame such a one, as worthy as a coin of refined gold? Even the gods praise him; by Brahma, too, is he praised.**

231. Let a man guard himself against irritability in bodily action; let him be controlled in deed. Abandoning bodily misconduct, let him practice good conduct in deed.

232. Let a man guard himself against irritability in speech; let him be controlled in speech. Abandoning verbal misconduct, let him practice good conduct in speech.

233. Let a man guard himself against irritability in thought; let him be controlled in mind. Abandoning mental misconduct, let him practice good conduct in thought.

234. The wise are controlled in bodily action, controlled in speech and controlled in thought. They are truly well-controlled.

Dhammapada chapter 17

do I misunderstand them?

How might I know if you do?

"Misunderstanding" might mean that your description doesn't match some kind of "truth", or "other evidence" -- but your description is the only evidence.

there are very few Buddhists in the culture where I live, but most of them seem to be constantly bragging

Could this perhaps be "selection bias" -- i.e. that people who brag are those who you find remarkable.

How representative are these people, anyway?

People who talk about their interests uninvited seems to me a fairly common human characteristic, not especially Buddhist -- people come out and talk about their religion; politics; favourite sports team; what kind of food they like or books they read or places they go.

Not a majority of people, but a large enough minority that it doesn't seem to me very surprising.

even if it's a technological topic in which I have experience and they don't

So that implies that the subject (Buddhism) isn't especially relevant (i.e. "they are like that" about every topic).

Unless you find it is only self-proclaimed Buddhists who talk like this.

but as they say "but it means so much more than that!"

Perhaps they sound enthusiastic about what they're learning -- as a technologist yourself, do you have no sympathy for that? -- but not especially skilled at explaining, which could be another topic, note the footnote to this sutta about teaching:

According to the Commentary, "hurting oneself" means exalting oneself. "Hurting others" means putting other people down.

they keep inserting words not from the language we're speaking in

I use words like that to think about Buddhism.

Not only Buddhism -- I find, working as a software developer in France, that (French) people normally use some English-origin words (like build as a noun) as technical jargon in everyday conversation -- even though there are French words to use, in conversations about other topics (other than software development).

No matter the topic, they sooner or later mention how enlightened they are.

Really?

I very rarely encounter someone who claims that. It seems to me inherently contradictory -- because Buddhist doctrine includes an element of "non-self" -- so I am uneasy with "I am" statements, especially "I am enlightened" (I too trip over "how are you?", don't always know how to answer).

Anyway though I try not to get drawn into the madness. Like if someone said, "I am clever" or "I am pretty", would that be as objectionable as "I am enlightened"? Is it a statement I want to resist, want to fight about?

And quite often in a condescending tone, that they are a being of much higher level than I am.

As for "condescending tone", I don't know what that's about. It sounds important, central to what you're asking -- about whether you're misunderstanding.

Coming out and lecturing someone ("I know more/better than you") might be described as one of several possible "ego defence mechanisms" people use.

Maybe a phase people go through until they learn to be better friends and better at socialising.

Do parents say it's stereotypical teenage behaviour, that some people are know-it-alls?

Are Buddhists supposed to feel superior compared to other people, and to brag about it?

Yes and no.

They're "supposed to" in the sense that it's predicted or observed that people, Buddhists, "will" -- not that they "should" -- and that that's a fault ...

Māna (Sanskrit, Pali; Tibetan: nga rgyal) is a Buddhist term that may be translated as "pride", "arrogance", or "conceit". It is defined as an inflated mind that makes whatever is suitable, such as wealth or learning, to be the foundation of pride. It creates the basis for disrespecting others and for the occurrence of suffering.

... and that it remains a problem (perhaps only intermittently) even for semi-enlightened people -- see How are 'conceit' and 'identity-view' not the same?

See also for example the answers to What is the difference between 'compassion' and 'pity'?

I'm of the opinion that nobody should ever call himself or herself a Buddhist under any circumstances. After all, the Buddha said that the true Dharma would disappear after 500 years, and that was many many centuries ago; that should be enough to resolve the debate.

On a more esoteric note, the Buddha taught that the self does not exist - so how can any individual person be a Buddhist, by his or her own nature? If I truly were a Buddhist, then I would understand that my own consciousness and individuality is an illusion. The entire cosmos is possessed of a Buddha nature, which is emptiness...

Practically speaking, the guideline for Buddhist monks is very strict; lifelong celibacy, veganism/vegetarianism (practically speaking, although a monk doesn't refuse meat if offered); cannot accept money if offered, as a gift, or perform paid work; cannot wear beautiful clothes, jewelry, fragrances; to say nothing of the emotional and spiritual demands of the monastic life, to be free of anger and selfishness under any and all conditions. The Mahayana teachings for lay believers are even more demanding; that a lay believer is to be just as enlightened as a monk, but without going forth and while carrying the responsibilities of a household. Certainly very few people ever make a serious attempt to attain enlightenment in this manner.

So don't call yourself a Buddhist. If somebody tells you they are a Buddhist, and you are feeling verbally combative and in a particularly un-Buddhist disposition, you can curtly inform them they are not! ;-)

Buddhist endgoal is that it shouldn't occur to one ''i am a woman', or 'i am a man' or 'i am anything at all', there being no 'i am' there don't come to be 'i am good/bad' or 'may i be' or 'may i not be like this or that', one to whom this does not occur is not going to compare oneself to others or brag about it.

One who compares himself to others and brags about things is going to have a lot of difficulty stilling his distractive thinking and won't progress easily.

This is a typical (and common) stage in spiritual development. In my country, I mainly see it in a wide variety of Christians; it's common enough in Buddhist circles as well, but the Buddhist population is small by comparison.

There are are a couple of things happening here that are worth considering when you run into such people:

1. Such people are generally good-natures enthusiasts: they have 'learned' something that makes them feel happy and good, and there is a natural human instinct to share such happiness and goodness with others. They are not trying to be bores — no one ever is — but they become bores because they can't see when they fail to connect with others.
2. At this stage, such people have not yet untangled their faith from social standing, political opinions, trust, and other conditional relationships. Their religious beliefs are part of their identity within the wider world; they use it to present themselves to others, and find themselves compelled to defend it when they see it being challenged.

The best approach is to accept such people as they are without allowing yourself to be unreasonably shifted. When they become more comfortable with you as a person, the need to present themselves in a particular light will fade, and the posturing will fade with it. Being annoyed won't help you or them, and allowing the conversation to deteriorate into a contest of wills is counterproductive.