I understood it as to recognise when their words are only packaged as “advice” from their bad experience (eg something general, vague, without specific useful logic you can take & apply to other situations, like “never get married”, “never invest”, “never build your own house”, etc).

That is not the same as a fully argumented logic (which the person might indeed have learned from their own mistake), like “if your partner explicitly promised that in the first week of marriage they will steal you money, murder your neighbors & pin it on you, and you would not want that, don’t marry them”.

Basically if someone opens a muffin shop & it goes out of business, and you are thinking of opening a muffin shop (“Muffin tops for muffin bottoms”), you are gonna need to know/understand why & how exactly it went out of business, not just that it went out of business, it’s a huge difference.
(It was in a neighborhood filled with lean muffintopless tops. So tweaking the business model only a little meant huge success.)

I disagree with OP in that it has to be trauma tho.
You can get stupid pushy advice what to do just bcs it worked by chance for someone (in a million) decades ago.