Why doesn't advice work?

Not everyone can give good advice, but there is people out there that can.

In my opinion, the best advisers are those that understand people's personalities and adapt for them. Most people out there do not like thinking, but some people think A LOT, even too much. You can not give the same advice to both groups: "Think before you act" only will work with the first group. It will be just wrong for the second. "Act impulsivelly without thinking" will be much better, because they will think too much by default.

The same applies to any aspect of personality: extroversion and introversion. Openness, domination level... Someone is a visionary or loves to start projects but hates following through.

Most of the time the best advice is stopping doing what you hate and finding someone who loves it. If you are introverted and love spending time on your own like reading books do not try to go to meet people all the time selling stuff, let extroverted people do that. If you are extroverted, do not stay at home programming alone for hours. Let introverted people do that.

If you have a company you need to be a visionary and have great ideas about what the customer needs but at the same time you need to execute and implement on those ideas. Visionary/executor usually are opposite personalities. You need both in order to succeed. Most people try hard to be what they are not instead of looking for complementary personalities. I have seen so many solo founders destroy their life just because of not understanding this simple thing.

Those that ignore personality differences will give terrible advice. I have seen parents forcing on their children advice on something that was very difficult for the parents to understand but the children have different personalities and they don't have the same problem. They don't need the same advice because they are different to there parents.

I give lots of advice but I always caveat with: "I don't know what I'm talking about; get as much advice as you can; in the end, make up your own damn mind."

This is spot on. I took a few counseling courses in college, and the thing I remember most was that we were instructed to never give advice. Ask questions, get clarifications, repeat back information, but don't say "Here's what I would do.."

In many ways it was similar to rubber duck debugging, as the goal seemed to be to facilitate the person being counseled on finding the solution on their own by seeing the problem with fresh eyes.

ODD has some really questionable aspects. Especially considering half of children diagnosed with it are also ADHD. I highly suspect the issue is more with the authority figures not knowing how to handle neurodivergence than the children themselves.

Many people tend to do the opposite of what they are told to do. In an individualist culture, this is normal.

It sounds good, but often still might be wrong. "That situation" includes details that still might not be clear. It's hard to communicate an entire frame of mind, and you might find that you'd in fact do something very different if you were confronted with it.