I've even realised a few things about my own language.

Why walk or jog of the car can do it for you?

There are. Unless your work requires almost constant creative reiteration over your mistakes on new topics, learning new things even when exhausted is still healthy for your brain.

It's easy to think, reading HN, that we're in some "post-knowledge" apocalypse, but that's just not the reality. It is, however, tragic that the irrationality of capitalism can be sustained so long, perhaps longer than some of us can stay solvent.

Imagine your perception as a VR headset, and any gadgets and apps are inserting a layer between you and your VR headset, making it worse.

The same goes with any augmenting technology you perceive not the real thing.

So, your friend was just expressing the general zeitgeist. But something to be aware of, is that “having that knowledge in one’s own head” might be unrewarding in time. Namely, once high-quality AI translation in near-real-time becomes the social norm, Chinese people (and most other people on earth) will become much less tolerant of a foreigner trying to speak their language imperfectly. You can already see something similar if you go to countries like Netherlands or Sweden and try to speak the local language at anything short of a high B2-level: people will complain you’re wasting their time compared to just using English.