Why am I such an idiot?

Intelligent, Smart, Moron, Imbecile, Oligophren. Stupid, Idiot.

I doesn't make any sense, does it? The above I mean.

Well, not yet. Not to you.

So, let's take them one by one, and see if that makes any sense.

You may have noticed, the title is in two sentences, clearly separated by a period. Now that has a meaning, we are actually talking about absolutely different subjects.

So let's take them subjects one by one and try to make some sense out of this title, if ever possible.

Intelligent:

(adj.) c. 1500, a back-formation from intelligence or else from Latin intelligentem (nominative intelligens), present participle of intelligere. Somebody able to understand things as they actually are.
In the human invented I.Q. scale, intelligent people belong amongst the normal people (normodotated people) at the upper eshalon, the best of the "normies", above that you are either a Savant (from French, Savoir; based on the latin sapere, to know) or a genius (Latin: [ˈɡɛnɪ.ʊs]; pl.: genii) is the individual instance of a general divine nature that is present in every individual person, place, or thing.
Basically intelligent is just somebody normal, that does not refuse to be what they are for some gain based on being ab normal.

Smart:

Smart definition: Energetic or quick in movement. Origin of Smart From Middle English smerten, from Old English smeortan ("to smart" ), from Proto-Germanic *smertanÄ… ("to hurt, ache" ), from Proto-Indo-European * (s)merd- ("to bite, sting" )
In other words, while you were sleeping in your walk something stung you back to reality, smartened you up, waked you up to being intelligent again and make a fast move to avoid being killed. Smart it is not a measure of intelligence, but rather a measure of how fast reality can wake you up from being stupid. Involuntary witt.

Moron:

From the Greek adjective μωρός (mōrós), meaning "slow, dull, foolish, stupid, silly," a moron is an less than intelligent normal, the lower end of normality, the opposite of intelligent but still on an I.Q. scale amongst the normal range of Normies. Normal, but kind of silly, slow and unreliable to do some cognitive thinking.

Imbecile:

The English adjective imbecile is, via French, from the Latin imbecillus, or imbecillis, meaning weak, feeble, in body or mind.
Bottom line, an imbecile is somebody that does not have enough brains to both sustain life and have some spare for thinking, at least minimally like a moron does. So by orders of priorities the little brains it has are used to sustain life, eating, drinking, shitting, pissing, walking and a minimal use of the hands, mainly to hold tight in slippery situations and to port food to the mouth.
Reading, forget it, writing, not even mention it, talking, minimally, rudimentary, and using basic concepts, reasoning, what is that even mean?

Oligophren:

Ultimately from Ancient Greek ὀλίγοι (olígoi, "few") +‎ Ancient Greek φρήν (phrḗn, "mind, soul")
OLIGOPHRENIA definition: less than normal mental development, which somehow puts Imbecility into the lower acceptable normal mental development, thou I would argue that Imbecility is right below the bar, it should not be the norm, so Oligophrenia is a worse case scenario of Imbecility.
The individual can still eat, drink, shit, piss, sleep, and... here is where it ends, hands and legs coordination might be somehow chaotic, not to mention brain to motion coordination, let alone purpose coordination of where we go and for what reason, that is already out the window together with conversation, reading, writing and critic thinking, as little as Imbecility allows, here is gone.
Not their fault, most of the time is a birth defect, so stop blaming it on themselves, blame mother nature instead, or even better, the politicians, they allow some weird substances to be sneaked in our food chain, drinks and medication, for their financial gain, and this is mostly a result of that, hence politicians fault.

Stupid:

The root word stupid, which can serve as an adjective or noun, comes from the Latin verb Stupere, for being numb or astonished, and is related to stupor. In Roman culture, the Stupidus was the professional fall guy in the theatrical mimes. In other words a perfectly "Normie" that pretended to be an Imbecile or Oligophrene for a while in front of an audience, for the money they paid him to act as a "Subnormal" human.
Stupidity is a lack of intelligence, understanding, reason, or wit, an inability to learn. It may be assumed or reactive.
A personal choice.

This is why you cannot cure stupid, you can cure illnesses, but not personal choices.

Technically a stupid is a "Normie", many times from the upper eshalon, very intelligent, that understood it can make a nice living playing the imbecile, executing instructions, orders and indications contrary to common sense, humanity, reality, personal convictions, for a nice living and a nicer pension. Be it in the service of government and administration, such as Politicians, Army, Secret Services, Police (and similar like Guardai, ICE, Gendarmes, Carabinieri,etc.) or of private entities (corporations, education, health, banking, NGO's, etc.).

As you could see Stupidity is not a natural condition at birth, unlike the above ones, but a conscious deliberate choice, and the only way to cure it is to make stupid poor, so their only chance to not be poor is to stop being stupid and start being normal again.

Idiot:

Just like Stupidity, it has nothing to do with conditions at birth, and if you think Idiot means Stupid, well, you are not only Stupid but also in-cult and uneducated.

There was a time people thought Stupidity is a result of poverty, education was expensive, so were books, and information was only flowing into rich privileged class hands.
I have bad news for you, now information is available online for free to just about anybody that has a smartphone or tablet at hand, even if second hand and the battery is dead hence they need to keep it plugged all the time, if you have a SIM contract in the device, or some WiFi access, information is there, abundant, free, overwhelming... so why are people still Stupid and have no clue what an Idiot is?

An Idiot, in modern use by stupid people, is a stupid or foolish person. But the truth is... you ought to study this before you make a fool of yourself:

The word "idiot" comes from the Greek noun ἰδιώτης (idiōtēs), meaning a private citizen or individual who does not participate in public life.
From ἴδιος (ídios, "one's own, pertaining to oneself, private").
In other words, somebody normal, that does not go around looking for "likes" on Facebook or in real life, a non public person, non politician. Somebody that keeps for himself and minds it's own business. Not a stupid, those love to collect "likes" in any way shape or form. Being an Idiot is the exact opposite of being Stupid.

You don't have to believe me, just go online, open Google translate (or other similar machine) choose to translate from Greek, to whatever language you prefer, modern Greek included, type in IDIOT and see what comes out, try IDIOTES, and see what you get, try IDIOTIKA PRAKTIKA, and ... well... do the other way around, chose to translate from your language to Greek and write anything you can imagine that starts with Private...rights, practices, choices, ideas, person, individual, and see how many of them in Greek contain the word IDIOT-something.