Advice
Upon reflection, giving advice is a pretty interesting thing that we humans do, or at least the way we approach it is. I think by and large we do it pretty inefficiently, but aren't cogniscent of our own biases or lack of knowledge to realise our mistakes.
Decision making is essentially about information - the more relevant information available, then by and large, the better the resulting decision will be. Giving advice is interesting because there is always an information mismatch, and the two parties will have differing experiences and knowledge on the matter at hand. Sometimes the amount of information is roughly equal, and sometimes one party simply has more information than the other. I think the majority of bad advice is borne of the giver having less than the receiver, although I could be swayed by the argument that in some edge cases less information could offer a certain amount of clarity compared to a large amount of unnecessary noise in the decision making process.
Conversely, when the giver has significantly more information than the receiver, the product is more often than not good advice - for example, if I were to ask my father for career advice. A particularly interesting flavour advice is that of relationship advice, where the informational mismatch is frequently huge. The giver essentially always has less advice than the receiver about the specific relationship, and relationships are full of complication and nuance. Perhaps the giver may have more experience with relationships in general, but intuitively I feel like he simply has less knowledge, but is unaware of that and happy to give advice regardless.
Really, giving advice should be about pooling information, and effectively communicating any knowledge that you have to the other party, without necessarily giving advice per se. That way, even if there is a mismatch, the receiver can still reasonably benefit from the advice of the giver, and make a more informed decision.
This post, if you hadn't guessed, has been a result of recently receiving both awful and amazing advice.