This seems much less about being casual or being a polymath and more about those who overestimate the value of their own input I’m leaving this comment only because I most often do not overestimate the value of my input and therefor don’t leave comments, but this seems the perfect place to deviate
I work in an academic field and took a strong and useful interest in another field. I really don't think I overestimate my abilities, I say things like I a jack of all trades and 'x think I'm great at y and y think I'm great at x'. But still people think especially talented. I even see quiet disagreement from experts in x or y who are maybe not so keen to criticise me publicly. I feel the issue is that others over es…
As much as people like to throw around the phrase "critical thinking", you're describing people being lazy and depending on their impression of you rather than evaluating the validity of what you have to say. It's a shortcut we all take because we dont have time (or ability) to be experts in everything so we listen to people we perceive to know what they're talking about.