Nobody ever explains how most social behavior works, IME; you’re supposed to somehow just know it.
And, apparently, a lot of people do. The rest of us have to study it from the outside, with varying degrees of success. Sometimes this results in our being able to explain something in words that others may be doing without consciously understanding that they’re doing it. Sometimes it just screws us up.
I don’t think I’d have articulated that one that way, though. I might have said, if you let other people see your weaknesses, they’re more likely to be comfortable showing you theirs; and more comfortable around you in general. @Spice_Weasel, is that the sort of thing that you meant?

Yeah, there’s plenty of jobs that women historically got stuck with because they were cleaning or food-preparation tasks that logically should have been handed to men. And not just the last century. Lots of such jobs that involved pounding, scrubbing or grinding things got traditionally assigned to women, when in terms of efficiency the gender with higher upper body strength should have been the one beating rugs and so on.
There’s a story I don’t have a cite for, which I read somewhere long before the internet, but which seems quite plausible to me:
Years ago, there used to be legal restrictions on how much weight women were allowed to lift in factory etc. jobs. The reason was claimed to be to protect women; but in practice it meant that women were barred from most such jobs that paid relatively well.
A group of people in charge of such regulations held a meeting, in a fancy restaurant. They were discussing that particular regulation, and most of them thought it necessary.
Then the one woman at the table looked at the waitress (gendered term deliberate), who had just brought over a tray with their main course; all on layers of good china as appropriate for that sort of restaurant. She had the waitress set the tray down without removing anything, and got them to bring a scale.
The loaded tray came in well over that weight limit. According to that story, that’s how that regulation got changed.
— Also many years ago: I bought a wood splitting maul at a hardware store. The people running the store gave me a hard time about it; they thought women weren’t supposed to be strong enough to use one. I said to them that if I’d been buying that large stockpot on the other shelf, they wouldn’t have thought anything about it; but carrying that stockpot when full was harder than swinging the maul — especially when the stockpot needed to be carried at arm’s length because it was hot.
The men rolled their eyes at me. But a woman who was also at the counter nodded enthusiastically.