Yep, very timely note to self.

Oh no what did he do :((. He knows what he did and this is not a surprise and if he suddenly gained a 'put actually 0 insolence into stuff he says' ability out of being in another world that would be a surprise. Also then other him might think he was an imposter. Other Jiang Cheng having about the same level of tolerance his has for when he is really trying to be properly obedient is very good, not all doms would be (or have been) that tolerant with him. This is a contrite and biddable-as-he-gets and properly appreciative Wei Ying.

Wei Wuxian will absolutely notice. But, nope, none of that, subspace brain, he is having no stupid reactions to other Jiang Cheng talking how Jiang Cheng usually talks just because it is currently a contrast to something.

...Wait he is getting to know the reason cultivation is usually started in childhood? He is! (This is going to get part of his brain suggesting that other Jiang Cheng must be at least a little sort of something like pleased with him, because he's telling him things; another part of his brain pointing out that other Jiang Cheng might just think he should know things about this world because he's in it, and knowing what causes problems at least makes him less likely to cause them by accident; and approximately all the parts of his brain distracted because alternative universe power information!!)

(aw that sucks about twenty. Though maybe there's a way around it that they haven't found here yet. Like other Jiang Cheng said it's not exactly the same thing as with a Foundation. Other Jiang Cheng said 'as the body is also growing'; it'd be pretty weird if golden cores were getting their 'is the body growing' signals from the Objective Font of Bodies Facts and not from the body they're in right. So potential step one, track down what they're getting as signals - did people already know about growth hormones at this point in history, he doesn't think so? (Wei Wuxian also doesn't actually know much about growth hormones. But he knows they exist!) Potential step two...)

(It takes him a moment to catch onto the live action metaphor, but he gets it.)

He has another moment like those times when he thought someone was speaking one of the languages he knows, and then his brain actually tried to resolve the syllables and they did not turn into words he understood at all. Then – ohhh! That kind of war. ...Or possibly not related to the war, but point is, something here is not at 'submissives are to be taught the appointed order of the world and show proper respect', and is at 'we don't respect those guys over there at all, look how much we don't do that'. - He's going to think this through some more later, right now he needs to answer the question.

Wei Wuxian partially suppresses a smile into his plate again. "Well, they're not all idiots - Sandu Shengshou." (It's a 'to be fair' kind of tone. These days a large part of the recipients of his opinions-at-length are Lan Zhan and Wen Ning, and it's gotten him into the habit.) 

Of course it's important to be aware and careful of dangers! (He does not say this like someone who came to this thought entirely independently). But that just means you have to figure out the way that really works, right, you can't go avoiding anything in the vague vicinity of 'something bad might happen'. If you did that you'd never have - surgery, or internal combustion engines, or fertilizer let alone dynamite! People get all nervous when it's power use because 'you can't understand it in exactly the same way as everything else' and 'it's hard to see what you're doing', but that doesn't mean it's different, if you - 

(This time he kind of forgets to keep a hold on the technical detail, but it should be possible to get a general idea.

The general idea might remind someone of a cultivator earnestly and passionately explaining that really, he has absolutely found a completely safe and reliable way to fly a sword into a hurricane. When said cultivator is both someone who could come up with that - not just if anyone could but if no one could. And also someone you would find in the infirmary, with the attendant healers explaining that he tried to fly a sword into a hurricane.)