I knew a kid that had ADHD. Unfortunately it was just a label - way for a kid to get everything. The kid didn't had ADHD imo, he was just spoiled and his parents were failing to do any parenting. The kid would eat whole mountain of sweets, drink cola all day, play games and scream and cry whenever he was prohibited something. In school he wasnt interested in learning and he basically would do nothing or play portable games all day. He would also not care for others and his needs would be always #1 before anything else.

Parents were really protective of him so they would fight with teachers whenever they would try to do something about it. The kid seemed to be pretty smart and he got all this figured out and used it a lot. But whenever he would be with people he didnt knew in a room, or with no-bullshit people, he would be actually quiet and behaving very good.

SOME ADHD cases sounds like just putting label on failed parenting to shut parents and avoid being sued by them for not doing any proper parenting.

Somebody was reading a list of ADHD warning signs to me from some self help book, which all perfectly described a mutual friend of ours: things like "interrupts other people while they're talking", "doesn't return phone calls", "no respect for authority", "always wants to be the center of attention", etc. I asked, "Maybe they're just an asshole? Isn't it possible to be an asshole without having ADHD?"

Oh, all right, I'll admit: it was really all about me. ;)

People LOVE to put labels on things. In many cases ADHD is one of them. This hurts people that REALLY have ADHD though.

You cherry-picked "kiddy" symptoms thereby creating a strawman. I am not a medical doctor, so I'm not going to tell you what it is or isn't -- but one of the symptoms you omitted, depression -- is NO FUCKING JOKE.

I am clinically diagnosed with having ADHD.

Some of the symptoms you name sound like they're picked up from a list of symptoms for diagnosing children with ADHD:

Dash around, touching or playing with anything and everything in sight, Have trouble sitting still during school and homework.

As a 20-something, relatively successful (founded and sold a company, work as an engineering consult for various companies, back in school getting my prereqs for medicine) male, I certainly am not playing with anything and everything in sight, nor do I dash around.

However, I do have a tendency to carry around something for my hands to play with -- a pen, squishy ball, my own fingers -- because they get restless. I also sometimes feel like I have a huge amount of excited energy balled up inside of me which I need to get out. I normally remedy this by exercising or running up and down a set of stairs a few times. One might say that my symptoms are adult versions of the childhood symptoms you point out.

As other people have mentioned, depression something that is often comorbid with ADHD. I personally have been severely depressed -- so much so that it caused "distress" (real-life problems) for an extended period of time. I became so tense, bored, disheartened, stressed-out by doing something I really loved. Depression followed. I won't say much else; if you'd like to understand this a bit more, let me know, and I'll spend some more time with a reply.

I made this reply further up, but in my case, it wasn't just being bored doing the unenjoyable tasks, but also the enjoyable tasks.

I need to second this. It isn't just being bored, it is being totally unable to function. There are things that I am interested in and REALLY want to learn/do/practice/build/enjoy but sometimes I am just totally incapable. I know what I want and I know what I need but I can't do it. Dr. Russell Barkley refers to ADHD as a performance disorder that was misnamed as an attention disorder and I tend to agree.