You will want to manipulate others to get confirmation of your acrobatics and always be on the lookout for disproof. This will lead to you limiting your life severely for fear of actually finding it.
-former smartness showoff who now acts betterer
Very sound advice.
Somewhat a tangent. I used to play a lot of poker. One angle that would work frequently to get information from people is exactly this.
Say something like "Ah you had AJ", even though you don't believe that. Then you might get a response "No I had __" or they might even show you their hand.
It's all tide to the need to prove how smart we are as humans.
It's a weird inversion, since the signals being defended are deeply illiberal: they exclude individualism, weirdness, inclusiveness, systems striving to be built on merit, etc etc.
I'm pretty familiar with this tendency because I come from a family who's pretty steeped in this kind of subculture. Growing up in CA and moving to the Bay as a teen, I absorbed the tech/Burning Man/CA memeplex of humanism and inherent equality and individualism way too deeply not to overwhelm my upbringing, but there are certain class markers I haven't shed, and un-self-conscious use of dense prose is one of them[1]. I actually did try to make my speech more casual when I became aware of these class markers during a period of teen rebellion, but changing how you communicate is a pretty complicated uphill battle, so I ended up with a weird hybrid of big words and idiomatic expressions (and lots of cursing, in verbal communication -_-)
[1] I want to emphasize again that this isn't quite an intelligence thing: my best friend is definitely smarter than me, and he speaks significantly more casually/colloquially than me because of his family's background.